nbu tuning guide

8/6/2019 NBU Tuning Guide

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N281842

Veritas NetBackup

Backup Planning and

Performance Tuning Guide

UNIX, Windows, and Linux

Release 6.0


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Veritas NetBackup NetBackupBackup Planning and Performance Tuning Guide

Copyright 2003 - 2006 Symantec Corporation. All rights reserved.

Veritas NetBackup 6.0PN: 281842

Symantec, the Symantec logo, and NetBackupare trademarks or registered trademarks ofSymantec Corporation or its affiliates in the U.S. and other countries. Other names may betrademarks of their respective owners.

Portions of this software are derived from the RSA Data Security, Inc. MD5Message-Digest Algorithm. Copyright 1991-92, RSA Data Security, Inc. Created 1991. Allrights reserved.

The product described in this document is distributed under licenses restricting its use,copying, distribution, and decompilation/reverse engineering. No part of this documentmay be reproduced in any form by any means without prior written authorization ofSymantec Corporation and its licensors, if any.

THIS DOCUMENTATION IS PROVIDED AS IS AND ALL EXPRESS OR IMPLIEDCONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIEDWARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE ORNON-INFRINGEMENT, ARE DISCLAIMED, EXCEPT TO THE EXTENT THAT SUCHDISCLAIMERS ARE HELD TO BE LEGALLY INVALID, SYMANTEC CORPORATION SHALLNOT BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES IN CONNECTIONWITH THE FURNISHING PERFORMANCE, OR USE OF THIS DOCUMENTATION. THEINFORMATION CONTAINED IN THIS DOCUMENTATION IS SUBJECT TO CHANGEWITHOUT NOTICE.

Symantec Corporation20330 Stevens Creek Blvd.Cupertino, CA 95014www.symantec.com

Printed in the United States of America.
http://www.symantec.com/http://www.symantec.com/


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Third-party legal noticesThird-party software may be recommended, distributed, embedded, or bundledwith this Symantec product. Such third-party software is licensed separately byits copyright holder. All third-party copyrights associated with this product arelisted in the accompanying release notes.

Technical supportFor technical assistance, visit http://support.veritas.com and select phone oremail support. Use the Knowledge Base search feature to access resources suchas TechNotes, product alerts, software downloads, hardware compatibility lists,and our customer email notification service.
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Contents

Section I Backup planning and configuration guidelines

Chapter 1 NetBackup capacity planning

New .........................................................................................................................12

Introduction ..........................................................................................................13

Analyzing your backup requirements ..............................................................14

Designing your backup system ..........................................................................16

Calculate the required data transfer rate for your backups ..................17

Calculate how long it will take to back up to tape ...................................18

Calculate how many tape drives are needed ............................................20Calculate the required data transfer rate for your network(s) .............21

Calculate the size of your NetBackup catalog .........................................22

Calculate the size of the EMM server ........................................................23

Calculate how much media is needed for full and incremental backups 25

Calculate the size of the tape library needed to store your backups ...26

Design your master backup server based on your previous findings ..27

Estimate the number of master servers needed ......................................29

Design your media server ...........................................................................31Estimate the number of media servers needed .......................................32

Design your NOM server .............................................................................33

Summary .......................................................................................................36

Questionnaire for capacity planning ................................................................37

Chapter 2 Master Server configuration guidelines

Managing NetBackup job scheduling ................................................................40Delays in starting jobs .................................................................................40

Delays in running queued jobs ...................................................................40

Job delays caused by unavailable media ...................................................41

Delays after removing a media server ......................................................41

Limiting factors for job scheduling ...........................................................41

Adjusting the servers network connection options ...............................42

Using NOM to monitor jobs ........................................................................ 43

Disaster recovery testing and job scheduling ..........................................43Miscellaneous considerations ............................................................................44

Processing of storage units ........................................................................44


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Disk staging .................................................................................................. 44

File system capacity .................................................................................... 45NetBackup catalog strategies ............................................................................ 45

Catalog backup types .................................................................................. 46

Guidelines for managing the catalog ........................................................ 46

Catalog backup not finishing in the available window .......................... 47

Catalog compression ...................................................................................48

Merging/splitting/moving servers ................................................................... 48

Moving the EMM server .............................................................................. 49

Guidelines for policies ........................................................................................ 49Include and exclude lists ............................................................................ 49

Critical policies .............................................................................................50

Schedule frequency ..................................................................................... 50

Managing logs ...................................................................................................... 50

Optimizing the performance of vxlogview .............................................. 50

Interpreting legacy error logs .................................................................... 51

Chapter 3 Media Server configuration guidelinesNetwork and SCSI/FC bus bandwidth ............................................................... 54

How to change the threshold for media errors ............................................... 54

Adjusting media_error_threshold ............................................................. 55

How to reload the st driver without rebooting Solaris .................................. 57

Media Manager drive selection ......................................................................... 58

Robot types and NetBackup port configuration ............................................. 58

Chapter 4 Media configuration guidelines

Dedicated or shared backup environment ....................................................... 60

Pooling ...................................................................................................................60

Disk versus tape ...................................................................................................60

Chapter 5 Database backup guidelines

Introduction ......................................................................................................... 64Considerations for database backups ............................................................... 64

Chapter 6 Best practices

Best practices: new tape drive technologies .................................................... 66

Best practices: tape drive cleaning ................................................................... 66

Best practices: storing tape cartridges ............................................................. 68

Best practices: recoverability .............................................................................68

Suggestions for data recovery planning .................................................. 69

Best practices: naming conventions ................................................................. 71


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Policy names .................................................................................................71

Schedule names ............................................................................................72Storage unit/storage group names ............................................................72

Section II Performance tuning

Chapter 7 Measuring performance

Overview ................................................................................................................76

Controlling system variables for consistent testing conditions ...................76Server variables ............................................................................................76

Network variables ........................................................................................77

Client variables .............................................................................................78

Data variables ...............................................................................................78

Evaluating performance .....................................................................................79

Evaluating UNIX system components ..............................................................84

Monitoring CPU load ...................................................................................84

Measuring performance independent of tape or disk output ...............84Evaluating Windows system components .......................................................85

Monitoring CPU load ...................................................................................86

Monitoring memory use .............................................................................87

Monitoring disk load ...................................................................................87

Chapter 8 Tuning the NetBackup data transfer path

Overview ................................................................................................................90The data transfer path ........................................................................................90

Basic tuning suggestions for the data path .....................................................91

NetBackup client performance ..........................................................................95

NetBackup network performance .....................................................................96

Network interface settings .........................................................................96

Network load .................................................................................................97

NetBackup media server network buffer size ..........................................97

NetBackup client communications buffer size ........................................ 99The NOSHM file .........................................................................................100

Using multiple interfaces .........................................................................101

NetBackup server performance .......................................................................102

Shared memory (number and size of data buffers) ..............................102

Parent/child delay values .........................................................................108

Using NetBackup wait and delay counters ............................................108

Fragment size and NetBackup restores ..................................................119

Other restore performance issues ...........................................................122NetBackup storage device performance .........................................................126


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Chapter 9 Tuning other NetBackup components

Multiplexing and multi-streaming .................................................................130

When to use multiplexing and multi-streaming ...................................130

Effects of multiple data streams on backup/restore ............................ 132

Encryption ..........................................................................................................133

Compression .......................................................................................................133

How to enable compression .....................................................................133

Using both encryption and compression .......................................................134

NetBackup java ...................................................................................................134Vault ....................................................................................................................134

Fast recovery with bare metal restore ............................................................135

Backing up many small files ............................................................................135

FlashBackup ...............................................................................................136

Chapter 10 Tuning disk I/O performance

Hardware performance hierarchy ..................................................................140

Performance hierarchy level 1 ................................................................142Performance hierarchy level 2 ................................................................142

Performance hierarchy level 3 ................................................................143



General notes on performance hierarchies ...........................................145

Hardware configuration examples .................................................................147

Tuning software for better performance ....................................................... 148

Chapter 11 OS-related tuning factors

Kernel tuning (UNIX) ........................................................................................152

Kernel parameters on Solaris 8 and 9 ....................................................152

Kernel parameters in Solaris 10 .............................................................. 154

Message queue and shared memory parameters on HP-UX ...............155

Kernel parameters on Linux ....................................................................157

Adjusting data buffer size (Windows) ............................................................157Other Windows issues .......................................................................................159

Appendix A Additional resources

Performance tuning information at vision online ...............................161

Performance monitoring utilities ...........................................................161

Freeware tools for bottleneck detection ................................................161

Mailing list resources ................................................................................162

Index 163


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Section I

Backup planning andconfiguration guidelines

Section I helps you lay the foundation of good backup performance through

planning and configuring your NetBackup installation. Section I also includes

some best practices.

Section I includes these chapters:

NetBackup Capacity Planning

Master Server Configuration Guidelines

Media Server Configuration Guidelines

Media Configuration Guidelines

Database Backup Guidelines

Best Practices

Note: For a discussion of tuning factors and general recommendations that may

be applied to an existing installation, see Section II.
http://../tuning_guide_60/NBU_Cap_Planning.pdfhttp://../tuning_guide_60/Master_Server.pdfhttp://../tuning_guide_60/Media_Server.pdfhttp://../tuning_guide_60/Media.pdfhttp://../tuning_guide_60/Database_Guidelines.pdfhttp://../tuning_guide_60/Best_practices.pdfhttp://../tuning_guide_60/Best_practices.pdfhttp://../tuning_guide_60/Database_Guidelines.pdfhttp://../tuning_guide_60/Media.pdfhttp://../tuning_guide_60/Media_Server.pdfhttp://../tuning_guide_60/Master_Server.pdfhttp://../tuning_guide_60/NBU_Cap_Planning.pdf


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Chapter 1

NetBackup capacityplanning

This chapter explains how to design your backup system as a foundation for

good performance.

This chapter includes the following sections:

Introduction on page 13

Analyzing your backup requirements on page 14

Designing your backup system on page 16

Questionnaire for capacity planning on page 37


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12 NetBackup capacity planningNew

NewVeritas NetBackup is a high-performance data protection application. Its

architecture is designed for large and complex distributed computing

environments. NetBackup provides a scalable storage management server that

can be configured for network backup, recovery, archival, and file migration

services.

This manual is for administrators who want to analyze, evaluate, and tune

NetBackup performance. This manual is intended to answer questions such as

the following: How big should the backup server be? How can the NetBackup

server be tuned for maximum performance? How many CPUs and tape drives

are needed? How to configure backups to run as fast as possible? How to

improve recovery times? What tools can characterize or measure how

NetBackup is handling data?

Note: Most critical factors in performance are based in hardware rather than

software. Hardware selection and configuration have roughly four times theweight that software has in determining performance. Although this guide

provides some hardware configuration assistance, it is assumed for the most

part that your devices are correctly configured.

Disclaimer

It is assumed you are familiar with NetBackup and your applications, operating

systems, and hardware. The information in this manual is advisory only,

presented in the form of guidelines. Changes to an installation undertaken as a

result of the information contained herein should be verified in advance for

appropriateness and accuracy. Some of the information contained herein may

apply only to certain hardware or operating system architectures.

Note: The information in this manual is subject to change.


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13NetBackup capacity planningIntroduction

IntroductionThe first step toward accurately estimating your backup requirements is a

complete understanding of your environment. Many performance issues can be

traced to hardware or environmental issues. A basic understanding of the entire

backup data path is important in determining the maximum performance you

can expect from your installation.

Every backup environment has a bottleneck. It may be a fast bottleneck, but it

will determine the maximum performance obtainable with your system.

Example:

Consider the configuration illustrated below. In this environment, backups run

slowly (in other words, they are not completing in the scheduled backup

window). Total throughput is eight to 10 megabytes per second.

What makes the backups run slowly? How can NetBackup or the environment be

configured to increase backup performance in this situation?

Figure 1-1 Dedicated NetBackup server

The explanation is that the LAN, having a speed of 100megabits per second, hasa theoretical throughput of 12.5 megabytes per second. In practice, 100BaseT

throughput is unlikely to exceed 70% utilization. Therefore, the best delivered

data rate is about 8 megabytes per second to the NetBackup server. The

throughput can be even lower than this, when TCP/IP packet headers,

TCP-window size constraints, router hops (packet latency for ACK packets

delays the sending of the next data packet), host CPU utilization, filesystem

overhead, and other LAN users activity are considered. Since the LAN is the

slowest element in the backup path, it is the first place to look in order toincrease backup performance in this configuration.


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14 NetBackup capacity planningAnalyzing your backup requirements

Analyzing your backup requirementsMany elements influence your backup strategy. You must analyze and compare

these factors and then make backup decisions according to your sites priorities.

When you plan your installations NetBackup capacity, ask yourself the

following questions:

Which systems need to be backed up?

It is important that you identify all systems that need to be backed up and

then list each system separately so that you can identify any that require

more resources to back up. Document which machines have local tape

drives or libraries attached and be sure to write down the model type of

each tape drive or library. In addition, record each host name, operating

system and version, database type and version, network technology (for

example, ATM or 100BaseT), and location.

How much data will be backed up?

Calculate how much data you need to back up. Include the total disk space

on each individual system, including that for databases. Remember to addthe space on mirrored disks only once.

By calculating the total size for all disks, you can design a system that takes

future growth into account. You should also consider the future by

estimating how much data you will need to back up in six months to a few

years from now.

Do you plan to back up databases or raw partitions?

If you are planning to backing up databases, you need to identify thedatabase engines, their version numbers, and the method that you will

use to back them up. NetBackup can back up several database engines

and raw file systems, and databases can be backed up while they are

online or offline. To back up any database while it is online, you need a

NetBackup database agent for your particular database engine.

If you use NetBackup Advanced Client to back up databases using raw

partitions, you are actually backing up as much data as the total size of

your raw partition. Also, remember to add the size of your databasebackups to your final calculations when figuring out how much data

you need to back up.

Will you be backing up specialty servers like MS-Exchange, Lotus

Notes, etc.?

If you are planning on backing up any specialty servers, you will need

to identify their types and application release numbers. As previously

mentioned, you may need a special NetBackup agent to properly back

up your particular servers.

What types of backups are needed and how often should they take place?


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15NetBackup capacity planningAnalyzing your backup requirements

The frequency of your backups has a direct impact on your:

Tape requirements

Data transfer rate considerations

Restore opportunities.

To properly size your backup system, you must decide on the type and

frequency of your backups. Will you perform daily incremental and weekly

full backups? Monthly or bi-weekly full backups?

How much time is available to run each backup?

It is important to know the window of time that is available for each backup.

The length of a window dictates several aspects of your backup strategy, for

example, you may want a larger window of time to back up multiple,

high-capacity servers. Or you may consider the use of advanced NetBackup

features such as synthetic backups, a local snapshot method, or

FlashBackup.

How long should backups be retained?

An important factor while designing your backup strategy is to consideryour policy for backup expiration. The amount of time a backup is kept is

also known as the retention period. A fairly common policy is to expire

your incremental backups after one month and your full backups after six

months. With this policy, you can restore any daily file change from the

previous month and restore data from full backups for the previous six

months. The length of the retention period depends on your own unique

requirements and business needs, and perhaps regulatory requirements.

However, keep in mind that the length of your retention period has adirectly proportional effect on the number of tapes you will need and the

size of your NetBackup catalog database. Your NetBackup catalog database

keeps track of all the information on all your tapes. The catalog size is

tightly tied in to your retention period and the frequency of your backups.

Also, database management daemons and services may become bottlenecks.

If backups are sent off site, how long must they remain off site?

If you plan to send tapes to an off site location as a disaster recovery option,

you must identify which tapes to send off site and how long they remain off

site. You might decide to duplicate all your full backups, or only a select few.

You might also decide to duplicate certain systems and exclude others. As

tapes are sent off site, you will need to buy new tapes to replace them until

they are recycled back from off site storage. If you forget this simple detail,

you will run out of tapes when you most need them.

What is your network technology?

If you are planning on backing up any system over a network, note thenetwork types that you will be using. The next section, Designing your


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16 NetBackup capacity planningDesigning your backup system

backup system, explains how to calculate the amount of data you can

transfer over those networks in a given time.Depending on the amount of data that you want to back up and the

frequency of those backups, you might want to consider installing a private

network just for backups.

What new systems will be added to your site in the next six months?

It is important to plan for future growth when designing your backup

system. By analyzing the potential future growth of your current or future

systems, you can insure the backup solution that you have accommodates

the kind of environment that you will have in the future. Remember to add

any resulting growth factor that you incur to your total backup solution.

Will user-directed backups or restores be allowed?

Allowing users to do their own backups and restores can reduce the time it

takes to initiate certain operations. However, user-directed operations can

also result in higher support costs and the loss of some flexibility.

User-directed operations can monopolize media and tape drives when you

most need them. They can also generate more support calls and trainingissues while the users become familiar with the new backup system. You

will need to decide whether allowing user access to some of your backup

systems functions is worth the potential costs.

Other factors to consider when planning your backup capacity include:

Data type: What are the types of data: text, graphics, database? How

compressible is the data? How many files are involved? Will the data be

encrypted? (Note that encrypted backups may run slower. See Encryptionon page 133 for more information.)

Data location: Is the data local or remote? What are the characteristics of

the storage subsystem? What is the exact data path? How busy is the

storage subsystem?

Change management: Because hardware and software infrastructure will

change over time, is it worth the cost to create an independent test-backup

environment to ensure your production environment will work with thechanged components?

Designing your backup systemFollowing an analysis of your backup requirements, you can begin designing

your backup system. Use the following subsections in the order shown below.


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17NetBackup capacity planningDesigning your backup system

Note: The ideas and examples that follow are based on standard and ideal

calculations. Your numbers will differ based on your particular environment,

data, and compression rates.

Calculate the required data transfer rate for your backups on page 17

Calculate how long it will take to back up to tape on page 18

Calculate how many tape drives are needed on page 20

Calculate the required data transfer rate for your network(s) on page 21

Calculate the size of your NetBackup catalog on page 22

Calculate the size of the EMM server on page 23

Calculate how much media is needed for full and incremental backups on

page 25

Calculate the size of the tape library needed to store your backups on

page 26 Design your master backup server based on your previous findings on

page 27

Estimate the number of master servers needed on page 29

Design your media server on page 31

Estimate the number of media servers needed on page 32

Design your NOM server on page 33

Summary on page 36

Calculate the required data transfer rate for your backupsThis is the rate of transfer your system must achieve to complete a backup of all

your data in the allowed time window. Use the following formula to calculate

your ideal data transfer rate for full and incremental backups:

Ideal data transfer rate = (Amount of data to back up) / (Backup window)

On average, the daily change in data for many systems is between 10 and 20

percent. Calculating a change of 20% in the (Amount of data to back up) and

dividing it by the (Backup window) will give you the backup data rate for

incremental backups.

If you are running cumulative-incremental backups, you need to take into

account which data is changing, since that affects the size of your backups. For

example, if the same 20% of the data is changing daily, your


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cumulative-incremental backup will be much smaller than if a completely

different 20% changes every day.

Example: Calculating your ideal data transfer rate during the week

Assumptions:

Amount of data to back up during a full backup = 500 gigabytes

Amount of data to back up during an incremental backup = 20% of a full

backup Daily backup window = 8 hours

Solution 1:

Full backup = 500 gigabytes

Ideal data transfer rate = 500 gigabytes/8 hours = 62.5 gigabytes/hour

Solution 2:

Incremental backup = 100 gigabytes

Ideal data transfer rate = 100 gigabytes/8 hours = 12.5 gigabytes/hour

To calculate your ideal data transfer rate during the weekends, divide the

amount of data that needs to be backed up by the length of the weekend backup

window.

Calculate how long it will take to back up to tapeOnce you know what your ideal data transfer rates are for backups, you can

figure out what kind of tape drive technology will meet your needs. Because you

also know the length of your available backup windows and the amount of data

that needs to be backed up, you can also calculate how many tape drives you will

need.

The table below lists the transfer rates for several tape drive technologies. The

values listed are those published by their individual manufacturers and those

observed in real-life situations. Keep in mind that device manufacturers list

optimum rates for their devices. In reality, it is quite rare to achieve those values

when a system has to deal with the overhead of the operating system, CPU loads,

bus architecture, data types, and other hardware and software issues.

The typical gigabytes/hour values from the Table 1-1Tape drive data transferrates table represent a range of real-life transfer rates for several devices, with

and without compression. When you design your backup system, consider the

nature of both your data and your environment. It is generally wise to estimate

on the conservative side when planning capacity. For instance, use the low end

of the typical gigabytes/hour range for your planning unless you have specific

reasons to use the higher numbers.

To calculate the length of your backups using a particular tape drive, use the

formula:
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Actual data transfer rate = (Amount of data to back up)/((Number of drives)

* (Tape drive transfer rate))

Example: Calculating the actual data transfer rate required

Assumptions:

Amount of data to back up during a full backup = 500 gigabytes

Daily backup window = 8 hours

Ideal transfer rate (data/(backup window)) = 500 gigabytes/8 hours = 62.5

gigabytes/hour

Solution 1:Tape drive = 1 drive, LTO gen 1

Tape drive transfer rate = 37 gigabytes/hour

Actual data transfer rate = 500 gigabytes/((1 drive) * (37 gigabytes/hour)) =

13.51 hours

With a data transfer rate of 37 gigabytes/hour, a single LTO gen 1 tape drive will

take 13.51 hours to perform a 500 gigabyte backup. A single LTO gen 1 tape

drive will not be able to perform your backup in eight hours. You will need a

faster tape drive or another LTO gen 1 tape drive.

Solution 2:

Tape drive = 1 drive, LTO gen 2


Backup length = 500 gigabytes/((1 drive) * (75 gigabytes/hour)) = 6.67 hours

With a data transfer rate of 75 gigabytes/hour, a single LTO gen 2 tape drive

will take 6.67 hours to perform a 500 gigabyte backup.

Table 1-1 Tape drive data transfer rates

Drive Theoretical

gigabytes/hour (nocompression)

Theoretical

gigabytes/hour (2:1compression)

Typical

gigabytes/hour

LTO gen 1 54 108 37-65

LTO gen 2 108 216 75-130

LTO gen 3 288 576 200-345

SDLT 320 57 115 40-70

SDLT 600 129 259 90-155

STK 9940B 108 252 (2.33:1) 75-100


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Depending on the several factors that can influence the transfer rates of your

tape drives, it is possible to obtain higher or lower transfer rates. The solutionsin the examples above are approximations of what you can expect.

Note also that a backup of encrypted data may take more time. See Encryption

on page 133 for more information.

Calculate how many tape drives are neededTo calculate how many tape drives you will need to perform your backups, use

the formula below and the typical gigabytes/hour transfer rates from the tableTape drive data transfer rates on page 19.

Number of drives = (Amount of data to back up) /((Backup window) * (Tape

drive transfer rate))

Example: Calculating the number of tape drives needed to perform abackup

Assumptions:

Amount of data to back up = 500 gigabytesBackup window = 8 hours

Solution 1:

Tape drive type = SDLT 320


Number of drives = 500 gigabytes/ ((8 hours) * (40 gigabytes/hour)) = 1.56 =

2 drives

Solution 2:Tape drive type = SDLT 600


Number of drives = 500 gigabytes/((8 hours) * (90 gigabytes/hour)) = 0.69 =

1 drive

Although it is quite straightforward to calculate the number of drives needed to

perform a backup, it is difficult to spread the data streams evenly across all

drives. To effectively spread your data, you have to experiment with various

backup schedules, NetBackup policies, and your hardware configuration. See

Basic tuning suggestions for the data path on page 91 to determine your

options.

Another important aspect of calculating how many tape devices you will need is

calculating how many tape devices you can attach to a drive controller.

When calculating the maximum number of tape drives that you can attach to a

controller, you must know the drive and controller maximum transfer rates as

published by their manufacturers. Failure to use maximum transfer rates foryour calculations can result in saturated controllers and unpredictable results.


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The table below displays the transfer rates for several drive controllers. In

practice, your transfer rates might be slower because of the inherent overheadof several variables including your file system layout, system CPU load, and

memory usage.

Calculate the required data transfer rate for your network(s)When designing your backup system to perform backups over a network, you

need to move data from your client(s) to your backup server(s) at a fast enough

rate to finish your backups within your allotted backup window. Using the

typical gigabytes/hour transfer rates from the table below, you can find out the

typical transfer rates of some fairly common network technologies. To calculate

the required data transfer rate, use the formula below:

Required network data transfer rate = (Amount of data to back up) / (Backup

window)

Table 1-2 Drive controller data transfer rates

Drive Controller Theoreticalmegabytes/second

Theoreticalgigabytes/hour

ATA-5 (ATA/ATAPI-5) 66 237.6

Wide Ultra 2 SCSI 80 288

iSCSI 100 360

1 Gigabit Fibre Channel 100 360

SATA/150 150 540

Ultra-3 SCSI 160 576


SATA/300 300 1080

Ultra320 SCSI 320 1152


Table 1-3 Network data transfer rates

Network Technology Theoretical gigabytes/hour Typical gigabytes/hour

10BaseT (switched) 3.6 2.7

100BaseT (switched) 36 32

1000BaseT (switched) 360 320


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To calculate your NetBackup catalog size, you need to know how much data you

will be backing up for full and incremental backups, how often these backupswill be performed, and for how long they will be retained. Here are two simple

formulas to calculate these values:

Data being tracked = (Amount of data to back up) * (Number of backups) *

(Retention period)

NetBackup catalog size = 120 * (number of files)

Note: If you select NetBackups True Image Restore option, your catalog will be

twice as large as a catalog without this option selected. True Image Restore

collects the information required to restore directories to their contents at the

time of any selected full or incremental backup. Because the additional

information that NetBackup collects for incremental backups is the same as that

of a full backup, incremental backups take much more disk space when you

collect True Image Restore information.

Example: Calculating the size of your NetBackup catalogAssumptions:

Amount of data to back up = 100 gigabytes

Incremental backups = 20% of all data

Full backups per month = 4

Retention period for full backups = 6 months

Incremental backups per month = 30

Retention period for incremental backups = 1 month

Solution:

Size of full backups = 100 gigabytes * 4 * 6 months = 2.4 terabytes

Size of incremental backups = (20% of 100 gigabytes) * 30 * 1 month = 600

gigabytes

Total data tracked = 2.4 terabytes + 600 gigabytes = 3 terabytes

NetBackup catalog size = 2% of 3 terabytes= 60 gigabytes

Based on the previous assumptions, it will take 60 gigabytes of disk space to hold

the catalog. Compression can reduce the size of your catalog to one-sixth or lessof its uncompressed size. When the catalog is decompressed, this is only done

for the images and time period of the particular system that you need to restore.

Calculate the size of the EMM serverBy default, the EMM server resides on the NetBackup master server. The

amount of space needed for the EMM server is determined by the size of the

NetBackup database (NBDB), as explained below.

24 N B k i l i


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Note: This space must be included when determining size requirements for a

master or media server, depending on where the EMM server is installed.

Space for the NBDB on the EMM server is required in the following two

locations:

UNIX

/usr/openv/db/data

/usr/openv/db/staging

Windows

install_path\NetBackupDB\datainstall_path\NetBackupDB\staging

Calculate the required space for the NBDB in each of the two directories, as

follows:

60 MB + (2 KB * number of volumes configured for EMM)

where EMMis the Enterprise Media Manager, and volumes are NetBackup

(EMM) media volumes. Note that 60 MB is the default amount of space needed

for the NBDB database used by the EMM server. It includes pre-allocated spacefor configuration information for devices and storage units.

Note: During NetBackup installation, the install script looks for 60 MB of free

space in the above /data directory; if there is insufficient space, the installation

fails. The space in /staging is only required when a hot catalog backup is run.

Example: Calculating the space needed for the EMM serverAssuming there are 1000 EMM volumes to back up, the total space needed for

the EMM server in /usr/openv/db/data is:

60 MB + (2 KB * 1000 volumes) = 62 MB

The same amount of space is required in /usr/openv/db/staging. The

amount of space required may grow over time as the NBDB database increases in

size.

Note: The above 60 MB of space is pre-allocated, and is derived from the

following separate databases that are consolidated into the EMM database in

NetBackup 6.0: globDB, ltidevs, robotic_def, namespace.chksum, ruleDB,

poolDB, volDB, mediaDB, storage_units, stunit_groups, SSOhosts, and media

errors database. See the NetBackup Release Notes, in the section titled

Enterprise Media Manager Databases, for additional details on files and

database information included in the EMM database.

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Calculate how much media is needed for full and incremental

backupsAs part of planning your backup strategy, calculate how many tapes will be

needed to store and retrieve your backups. The number of tapes that you will

need depends on:

The amount of data that you are backing up

The frequency of your backups

The planned retention periods The capacity of the media used to store your backups.

If you expect your site's workload to increase over time, you can ease the pain of

future upgrades by planning for expansion. Design your initial backup

architecture so it can evolve to support more clients and servers. Invest in the

faster, higher-capacity components that will serve your needs beyond the

present.

A simple formula for calculating your tape needs is shown here:Number of tapes = (Amount of data to back up) / (Tape capacity)

To calculate how many tapes will be needed based on all your requirements, the

above formula can be expanded to

Number of tapes = ((Amount of data to back up) * (Frequency of backups) *

(Retention period)) / (Tape capacity)

Example: Calculating how many tapes are needed to store all yourbackups

Preliminary calculations:

Size of full backups = 500 gigabytes * 4 (per month) * 6 months = 12terabytes

Table 1-4 Tape capacities

Drive Theoretical gigabytes

(no compression)

Theoretical gigabytes

(2:1 compression)

LTO gen 1 100 200

LTO gen 2 200 400

LTO gen 3 400 800

SDLT 320 160 320

SDLT 600 300 600

STK 9940B 200 400

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Size of incremental backups = (20% of 500 gigabytes) * 30 * 1 month = 3

terabytesTotal data tracked = 12 terabytes + 3 terabytes = 15 terabytes

Solution 1:

Tape drive type = LTO gen 1

Tape capacity without compression = 100 gigabytes

Tape capacity with compression = 200 gigabytes

Without compression:

Tapes needed for full backups = 12 terabytes/100 gigabytes = 120

Tapes needed for incremental backups = 3 terabytes/100 gigabytes = 30Total tapes needed = 120 + 30 = 150 tapes

With 2:1 compression:


Tapes needed for incremental backups = 3 terabytes/200 gigabytes = 15

Total tapes needed = 60 + 15 = 75 tapes

Solution 2:

Tape drive type = LTO gen 3Tape capacity without compression = 400 gigabytes

Tape capacity with compression = 800 gigabytes

Without compression:


Tapes needed for incremental backups = 3 terabytes/400 gigabytes = 7.5 ~=

8


With 2:1 compression:Tapes needed for full backups = 12 terabytes/800 gigabytes = 15

Tapes needed for incremental backups = 3 terabytes/800 gigabytes = 3.75

~= 4


Calculate the size of the tape library needed to store your backups

To calculate how many robotic library tape slots are needed to store all yourbackups, take the number of tapes for backup calculated in Calculate how much

media is needed for full and incremental backups on page 25 and add tapes for

catalog backup and cleaning:

Tape slots needed = (Number of tapes needed for backups) + (Number of

tapes needed for catalog backups) + 1 (for a cleaning tape)

A typical example of tapes needed for catalog backup is 2.

Additional tapes may be needed for the following:



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If you plan to duplicate tapes or to reserve some media for special

(non-backup) use, add those tapes to the above formula. Add tapes needed for future data growth. Make sure your system has a

viable upgrade path as new tape drives become available.

Design your master backup server based on your previous findingsTo design and configure a master backup server, you must:

Perform an initial backup requirements analysis, as outlined in the section

Analyzing your backup requirements on page 14.

Perform the calculations outlined in the previous steps of the current

section.

Designing a backup server becomes a simple task once the basic design

constraints are known:

Amount of data to back up

Size of the NetBackup catalog

Number of tape drives needed

Number of networks needed

Given the above, a simple approach to designing your backup server can be

outlined as follows:

Acquire a dedicated server

Add tape drives and controllers (for saving your backups)

Add disk drives and controllers (for OS and NetBackup catalog)

Add network cards

Add memory

Add CPUs



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p p y p gDesigning your backup system

Figure 1-2 Backup server hardware component

In some cases, it may not be practical to design a generic server to back up all ofyour systems. You might have one or several large servers that cannot be backed

up over a network within your backup window. In such cases, it is best to back up

those servers using their own locally-attached tape drives. Although this section

discusses how to design a master backup server, you can still use its information

to properly add the necessary tape drives and components to your other servers.

The next example shows how to configure a master server using the design

elements gathered from the previous sections.

Example: Designing your master backup server

Assumptions:

Amount of data to back up during full backups = 500 gigabytes

Amount of data to back up during incremental backups = 100 gigabytes

Tape drive type = SDLT 600

Tape drives needed = 1

Network technology = 100BaseTNetwork cards needed = 1

Size of NetBackup catalog after 6 months = 60 gigabytes (from Example:

Calculating the size of your NetBackup catalog on page 23)

Solution (the following values are based on the table CPUs needed per

master/media server component and Memory needed per master/media

server component on page 32):

CPUs needed for network cards = 1

CPUs needed for tape drives = 1

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Designing your backup system

CPUs needed for OS = 1

Total CPUs needed = 1 + 1 + 1 = 3

Memory needed for network cards = 16 megabytes

Memory needed for tape drives = 128 megabytes

Memory needed for OS and NetBackup = 1 gigabyte

Total memory needed = 16 + 128 + 1000 = 1.144 gigabytes

Based on the above, your master server needs 3 CPUs and 1.144 gigabytes of

memory. In addition, you need 60 gigabytes of disk space to store your

NetBackup catalog, along with the necessary disks and drive controllers to

install your operating system and NetBackup (2 gigabytes should be ample formost installations). This server also requires one SCSI card, or another, faster,

adapter for use with the tape drive (and robot arm) and a single 100BaseT card

for network backups.

When designing your backup server solution, begin with a dedicated server for

optimum performance. In addition, consult with your servers hardware

manufacturer to ensure that the server can handle your other components. In

most cases, servers have specific restrictions on the number and mixture of

hardware components that can be supported concurrently. Overlooking this last

detail can cripple even the best of plans.

Estimate the number of master servers neededOne of the key elements in designing your backup solution is estimating how

many master servers are needed. As a rule, the number of master servers is

proportional to the number of media servers. To determine how many master

servers are required, consider the following:

The master server must be able to periodically communicate with all its

media servers. If there are too many media servers, master server

processing may be overloaded.

Consider business-related requirements. For example, if an installation has

different applications which require different backup windows, a single

master may have to run backups continually, leaving no spare time for

catalog cleaning, catalog backup, or maintenance.

If at all possible, design your configuration with one master server per

firewall domain. In addition, do not share robotic tape libraries between

firewall domains.

As a rule, the number of clients (separate physical hosts) per master server

is not a critical factor for NetBackup. Ordinary backup processing

performed by each client has little or no impact on the NetBackup server,

unless, for instance, the clients all have database extensions or are trying torun ALL_LOCAL_DRIVES at the same time.



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Plan your configuration so that it contains no single point of failure.

Provide sufficient redundancy to ensure high availability of the backup

process. Having more tape drives or media may reduce the number of media

servers needed per master server.

Consider limiting the number of media servers handled by a master to the

lower end of the estimates in the following table, Table 1-5Number of media

servers supported by a master server.

Although a well-managed NetBackup environment can handle more media

servers than the numbers listed in this table, you may find your backup

operations more efficient and manageable with fewer but larger mediaservers. The variation in the number of media servers per master server for

each scenario in the table depends on the number of jobs submitted,

multiplexing, multi-streaming, and network capacity.

For information on designing a master server, refer to Design your master

backup server based on your previous findings on page 27.

Note: This table provides a rough estimate only, as a guideline for initialplanning. Note also that the RAM amounts shown below are for a base

NetBackup installation; RAM requirements vary depending on the NetBackup

features, options, and agents being used.

Table 1-5 Number of media servers supported by a master server

Master

Server Type

RAM Number of

Processors

Master

Backups

Media Server

Backups

Media

Configuration

Number of

MediaServers PerMaster

Server

Solaris 2 gigabytes 4 Not backing

up clients

Media server

backing up

itself only

10 - 20 tape

drives in not

more than 2

libraries

25 - 40

Solaris 4 gigabytes 4 Not backing

up clients

Media server

backing up

itself only

10 - 20 tape

drives in not

more than 2

libraries

35 - 50

Solaris 8+ gigabytes 4 Not backing

up clients

Media server

backing up

network

clients

20 - 40 tape

drives in not

more than 2

libraries

50 -70



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Design your media serverYou can use a media server not only to back up itself, but also to back up other

systems and reduce or balance the load on your master server. With NetBackup,

the robotic control of a library can be on either the master server or the media

server.

Windows 2 gigabytes 4 Not backing

up clients

Media server

backing up

itself only

15 - 30 tape

drives in not

more than 2

libraries

10+

Windows 4 gigabytes 4 Not backing

up clients

Media server

backing up

itself only

20 - 40 tape

drives in not

more than 2

libraries

20+

Windows 8+ gigabytes 4 Not backing

up clients

Media server

backing up

networkclients

40 - 128 tape

drives in not

more than 2libraries

50+

Table 1-5 Number of media servers supported by a master server

MasterServer Type

RAM Number ofProcessors

MasterBackups

Media ServerBackups

MediaConfiguration

Number ofMedia

Servers PerMaster

Server

Table 1-6 CPUs needed per master/media server component

Component How many and what kind of component Number of CPUs per

component

Network cards 2-3 100BaseT cards 1

5-7 10BaseT cards 1

1 ATM card 1

1-2 Gigabit Ethernet cards with coprocessor 1

Tape drives 2 LTO gen 3 drives 1

2-3 SDLT 600 drives 1

2-3 LTO gen 2 drives 1

3-4 LTO gen 1 drives 1



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The information in the above tables is a rough estimate only, intended as a

guideline for initial planning.

In addition to the above media server components, you must also add the

necessary disk drives to store the NetBackup catalog and your operating system.The size of the disks needed to store your catalog depends on the calculations

explained earlier under Calculate the size of your NetBackup catalog on

page 22.

Estimate the number of media servers neededHere are some guidelines for estimating the number of media servers needed:

I/O performance is generally more important than CPU performance.

Consider CPU, I/O, and memory expandability when choosing a server.

Consider how many CPUs are needed (see CPUs needed per master/media

server component on page 31). Here are some general guidelines:

Experiments (with Sun Microsystems) have shown that a useful,

conservative estimate is 5MHz of CPU capacity per 1MB/second of data

movement in and out of the NetBackup media server. Keep in mind that the

operating system and other applications also use the CPU. This estimate is

for the power available to NetBackup itself.

OS and NetBackup 1

Table 1-6 CPUs needed per master/media server component

Component How many and what kind of component Number of CPUs percomponent

Table 1-7 Memory needed per master/media server component

Component Type of component Memory per component

Network cards 16 megabytes

Tape drives LTO gen 3 drive 256 megabytes

SDLT 600 drive 128 megabytes

LTO gen 2 drive 128 megabytes

LTO gen 1 drive 64 megabytes

OS and NetBackup 1 gigabyte

OS, NetBackup, and NOM 1 or more gigabytes

NetBackup multiplexing 8 megabytes * (# streams) * (# drives)

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Example:

A system backing up clients over the network to a local tape drive at the

rate of 10MB/second would need 100MHz of available CPU power:

50MHz to move data from the network to the NetBackup server

50MHz to move data from the NetBackup server to tape.

Consider how much memory is needed (see Memory needed per

master/media server component on page 32).

At least 512 megabytes of RAM is recommended if the server is running a

Java GUI. NetBackup uses shared memory for local backups. NetBackup

buffer usage will affect how much memory is needed. See the Tuning theNetBackup data transfer path chapter for more information on NetBackup

buffers.

Keep in mind that non-NetBackup processes need memory in addition to

what NetBackup needs.

A media server moves data from disk (on relevant clients) to storage

(usually disk or tape). The server must be carefully sized to maximize

throughput. Maximum throughput is attained when the server keeps its

tape devices streaming. (For an explanation of streaming, see Tape

streaming on page 126.)

Media server factors to consider for sizing include:

Disk storage access time

Adapter (for example, SCSI) speed

Bus (for example, PCI) speed

Tape device speed Network interface (for example, 100BaseT) speed

Amount of system RAM

Other applications, if the host is non-dedicated

The platform chosen must be able to drive all network interfaces and keep all

tape devices streaming.

Design your NOM serverBefore setting up a NetBackup Operations Manager (NOM) server, review the

recommendations and requirements listed in the installation chapter of the

NetBackup Operations Manager Getting Started Guide. Note, for example:

NOM server software does not have to be installed on the same server as

NetBackup 6.0 master server software. Since the NOM server is also a web

server, installing NOM on a master server may impact security and

performance. (The guidelines provided here assume that the NOM server is

a standalone host not acting as a master server.)

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Symantec recommends that you not install NOM software on a clustered

NetBackup master server.

Sizing considerations

The size of your NOM server depends largely on the number of NetBackup

objects that NOM manages. See the following table.

Based on the above factors, the following NOM server components should be

sized accordingly.

The next section describes the NOM database and how it affects disk space

requirements, followed by overall sizing guidelines for NOM.

NOM database

The Sybase database used by NOM is similar to that used by NetBackup and isinstalled as part of the NOM server installation.

The disk space needed for the initial installation of NOM depends on the

volume of data initially loaded onto the server, based on the following:

number of policy data records, number of job data records, number of media

data records, and number of catalog image records.

The rate of NOM database growth depends on the quantity of data being

managed: policy data, job data, media data, and catalog data.

Factors in determining NOM server size

Number of master servers to manage(the number of media servers is irrelevant)

Number of policies

Number of jobs run per day

Number of media

Number of catalog images

NOM server components

Disk space (installed NOM binary + NOM database, described below)

Type and number of CPUs

RAM



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Sizing guidelines

The following guidelines are presented in groups based on the number of objectsthat your NOM server manages.

It is assumed that your NOM server is a standalone host (the host is not acting as

a NetBackup master server).

Note: Symantec recommends multiple NOM servers for deployments larger than

those described in the following guidelines.

Note: The guidelines are intended for basic planning purposes, and do not

represent fixed recommendations or restrictions.

In the following table, find the installation category that matches your site,

based on number of master servers that your NOM server will manage, number

of jobs per day, and so forth. Then consult the following table for NOM sizing

guidelines.

Using the NetBackup installation category from above (A, B, C, D), read across to

the recommended NOM server capacities.

Table 1-8 NOM sizing guidelines

NetBackup

installation

category

Master

servers

Jobs per

day

Policies Alerts per

day

Media

A 1 - 3 200 - 500 200 - 300 100 - 200 5000

B 3 - 5 500 - 1000 300 - 500 200 - 300 10000

C 5 - 7 1000 - 5000 1000 - 4000 500 - 800 20000

D 8 - 10 5000 - 8000 4000 - 8000 800 - 3000 30000

Table 1-9 NOM server capacities

NetBackup

installation

category

OS CPU type Number

of CPUs

RAM Disk

space

A Windows Pentium V 2 2 GB 80 GB

Solaris Sun Sparc 1200 MHz 1 2 GB 80 GB

B Windows Pentium V 2 2 GB 80 GB



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SummaryUsing the guidelines provided in this chapter, design a solution that can do a full

backup and incremental backups of your largest system within your time

window. The remainder of the backups can happen over successive days.Eventually, your site may outgrow its initial backup solution. By following these

guidelines, you can add more capacity at a future date without having to

redesign your basic strategy. With proper design and planning, you can create a

backup strategy that will grow with your environment.

As outlined in the previous sections, the number and location of the backup

devices are dependent on a number of factors.

The amount of data on the target systems, The available backup and restore windows,

The available network bandwidth, and

The speed of the backup devices.

If one drive causes backup window time conflicts, another can be added,

providing an aggregate rate of two drives. The trade-off is that the second drive

imposes extra CPU, memory, and I/O loads on the media server.

If you find that you cannot complete backups in the allocated window, one

approach is to either increase your backup window or decrease the frequency of

your full and incremental backups.

Another approach is to reconfigure your site to speed up overall backup

performance. Before you make any such change, you should understand what

determines your current backup performance. List or diagram your site network

and systems configuration. Note the maximum data transfer rates for all the

components of your backup configuration and compare these against the rateyou must meet for your backup window. This will identify the slowest


C Windows Pentium V 4 4 GB 80 GB


D Windows Pentium V 4 4 GB 80 GB


Table 1-9 NOM server capacities

NetBackupinstallation

category

OS CPU type Numberof CPUs

RAM Diskspace

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components and, consequently, the cause of your bottlenecks. Some likely areas

for bottlenecks include the networks, tape drives, client OS load, and filesystem

fragmentation.

Questionnaire for capacity planningUse the following questionnaire to fill in information about the characteristics

of your systems and how they will be used. This data can help determine your

NetBackup client configurations and backup requirements.

Table 1-10 Backup questionnaire

Question Explanation

System name Any unique name to identify the machine. Hostname or any unique name for each

system.

Vendor The hardware vendor who made the system (for example, Sun, HP, IBM, generic PC)

Model For example: Sun E450, HP K580, Pentium II 300MHZ, HP Proliant 8500

OS version For example: Solaris 9, HP-UX 11i, Windows 2000 DataCenter

Building / location Identify physical location by room, building, and/or campus.

Total storage Total available internal and external storage capacity.

Used storage Total used internal and external storage capacity - if the amount of data to be backed up

is substantially different from the amount used, please note that.

Type of external array For example: Hitachi, EMC, EMC CLARiiON, STK.

Network connection For example, 10/100MB, Gigabit, T1. It is important to know if the LAN is a switched

network or not.

Database (DB) For example, Oracle 8.1.6, SQLServer 7.

Hot backup required? If so, this requires the optional database agent if backing up a database.

Key application For example: Exchange server, accounting system, software developer's code repository,

NetBackup critical policies.

Backup window For example: incrementals run M-F from 11PM to 6AM, Fulls are all day Sunday. This

information helps determine where potential bottlenecks will be and how to configure a

solution.

Retention policy For example: incrementals for 2 weeks, full backups for 13 weeks. This information will

help determine how to size the number of slots needed in a library.

Existing backup media Type of media currently used for backups.

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Comments? Any special situations to be aware of? Any significant patches on the operating system?

Will the backups be over a WAN? Do the backups need to go through a firewall?

Table 1-10 Backup questionnaire (continued)

Question Explanation

Chapter 2


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Chapter 2

Master Server

configuration guidelines

This chapter provides guidelines and recommendations for better performance

on the NetBackup master server.

This chapter includes the following sections: Managing NetBackup job scheduling on page 40

Miscellaneous considerations on page 44

Merging/splitting/moving servers on page 48

Guidelines for policies on page 49

Managing logs on page 50

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Managing NetBackup job schedulingThis section discusses issues related to NetBackup job scheduling.

Delays in starting jobsThe NetBackup Policy Execution Manager (nbpem) may not begin a backup at

exactly the time a backup policy's schedule window opens. This can happen

when you define a schedule or modify an existing schedule with a window start

time close to the current time.

For instance, suppose you create a schedule at 5:50 PM, specifying that backups

should start at 6:00 PM. You complete the policy definition at 5:55 PM. At 6:00

PM, you expect to see a backup job for the policy start, but it does not. Instead,

the job takes another several minutes to start.

The explanation is that NetBackup receives and queues policy change events as

they happen, but processes them periodically as configured in the Policy Update

Interval setting under Host Properties > Master Server > Properties > Global

Settings (the default is 10 minutes). The backup does not start until the firsttime NetBackup processes policy changes after the policy definition is

completed at 5:55 PM. NetBackup may not process the changes until 6:05 PM.

For each policy change, NetBackup determines what needs to be done and

updates its work list accordingly.

Delays in running queued jobs

If jobs remain in the queue and only one job runs at a time, make sure thefollowing attributes are set to allow jobs to run simultaneously:

Host Properties > Master Server > Properties > Global Attributes >

Maximumjobs per client (should be greater than 1).

Host Properties > Master Server > Properties > Client Attributes setting

for Maximum data streams (should be greater than 1).

Policy attribute Limit jobs per policy (should be greater than 1).

Policy schedule attribute Media multiplexing (should be greater than 1).

Check the storage unit properties:

Is the storage unit enabled to use multiple drives (Maximum concurrent

write drives)? If you want to increase this value, remember to set it to

fewer than the number of drives available to this storage unit.

Otherwise, restores and other non-backup activities will not be able to

run while backups to the storage unit are running.

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Is the storage unit enabled for multiplexing (Maximum streams per

drive)? You can write a maximum of 32 jobs to one tape at the same

time.

Job delays caused by unavailable mediaIf the media in a storage unit are not configured or are unusable (such as being

expired, or the maximum mounts setting was exceeded, or the wrong pool was

selected), the job will fail if no other storage units are usable. If media are

unavailable, new media will have to be added, or the media configuration will

have to be changed to make media available (such as changing the volume pool

or the maximum mounts).

If the media in a storage unit are usable but are currently busy, the job will be

queued. The NetBackup Activity Monitor should display the reason for the job

queuing, such as media are in use. If the media are in use, the media will

eventually stop being used and the job will run.

Delays after removing a media serverA job may be queued by the NetBackup Job Manager (nbjm) if the media server is

not available. This is not because of communication time-outs, but because EMM

knows the media server is down and the NetBackup Resource Broker (nbrb)

queues the request to be retried later.

If a media server is configured in EMM but has been physically removed,

powered off, or disconnected from the network, or if the network is down for any

reason, the media and device selection logic of EMM will queue the job if noother media servers are available. The Activity Monitor should display the

reason for the job queuing, such as media server is offline. Once the media

server is online again in EMM, the job will start. In the meantime, if other media

servers are available, the job will run on another media server.

If a media server is not configured in EMM (removed from the configuration),

regardless of the physical state of the media server, EMM will not select that

media server for use. If no other media servers are available, the job will fail.

Limiting factors for job schedulingFor every backup submitted, there may be one bprd process for the duration of

the job. When many requests are submitted to NetBackup simultaneously,

NetBackup will increase its use of memory and may eventually impact the

overall performance of the system. This type of performance degradation is

associated with the way a given operating system handles memory requests. It

may affect the functioning of all applications running on the system in question,

not just NetBackup.

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Note: The Activity Monitor may not update if there are many (thousands of) jobs

to view. If this happens, you may need to change the memory setting using theNetBackup Java command jnbSA with the -mx option. Refer to the

INITIAL_MEMORY, MAX_MEMORY subsection in the NetBackup System

Administrators Guide for UNIX and Linux, Volume I. Note thatthis situation

does not affect NetBackup's ability to continue running jobs.

Adjusting the servers network connection optionsWhen running many simultaneous jobs, the CPU utilization of the master server

may become very high. To reduce utilization and improve performance, adjust

the network connection options for the local machine on the Host Properties >

Master Server > Master Server Properties > Firewall display in the NetBackup

Administration Console (shown below), or you can add the following bp.conf

entry to the UNIX master server.

CONNECT_OPTIONS = localhost 1 0 2

For an explanation of the CONNECT_OPTIONS values, refer to the NetBackupSystem Administrators Guide for UNIX and Linux, Volume II.

The NetBackup Troubleshooting Guidealso provides information on network

connectivity issues.

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Using NOM to monitor jobs

The NetBackup Operations Manager (NOM) can be used to monitor theperformance of NetBackup jobs. NOM can also manage and monitor dozens

of NetBackup installations spread across multiple locations. Some of the

features provided by NOM are the following:

Web-based interface for efficient, remote administration across multiple

NetBackup servers from a single, centralized console.

Policy-based alert notification, using predefined alert conditions to specify

typical issues or thresholds within NetBackup. Flexible reporting, on issues such as backup performance, media utilization,

and rates of job success.

Consolidated job and job policy views per server (or group of servers), for

filtering and sorting job activity.

For more information on the capabilities of NOM, refer to the NOM online help

in the Administration console, or see the NetBackup Operations Manager Getting

Started Guide.

Disaster recovery testing and job schedulingThe following techniques may help in your disaster recovery testing.

Prevent the expiration of empty media.

a Go to the following directory:

UNIXcd /usr/openv/netbackup/bin

Windows

install_path\NetBackup\bin

b Enter the following:

mkdir bpsched.dcd bpsched.d

echo 0 > CHECK_EXPIRED_MEDIA_INTERVAL

Prevent the expiration of images

a Go to the following directory:

UNIX

cd /usr/openv/netbackup

Windows

cd install_path\NetBackup

b Enter the following:

UNIX

touch NOexpire

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Windows

echo 0 > NOexpire

Prevent backups from starting by shutting down bprd (NetBackup Request

Manager). This will suspend scheduling of new jobs by nbpem. To shut

down bprd, you can use the Activity Monitor in the NetBackup

Administration Console.

Restart bprd to resume scheduling.

Miscellaneous considerationsConsider the following issues when planning for or troubleshooting NetBackup.

Processing of storage unitsNetBackup storage units are processed in alphabetical order. You can affect how

storage units are selected and therefore when media servers are used by being

aware of the alphabetical order of the name of each storage unit. You can also

have some control over load balancing by using storage unit groups.

Storage unit groups contain a list of storage units that are available for that

policy to use. A storage unit group can be configured to use storage units in any

of three ways, in the New Storage Unit Group dialog of the NetBackup

Administration Console.

Use storage units in the order in which they are listed in the group.

Choose the least recently selected storage unit in the group.

Configure the storage unit group as a failover group. This means the first

storage unit in the group will be the only storage unit used. If the storage

unit is busy, then backups will queue. The second storage unit will only be

used if the first storage unit is down.

Disk staging

With disk staging, images can be created on disk initially, then copied later toanother media type (as determined in the disk staging schedule). The media type

for the final destination is typically tape, but could be disk. This two-stage

process leverages the advantages of disk-based backups in the near term, while

preserving the advantages of tape-based backups for long term.

Note that disk staging can be used to increase backup speed. For more

information, refer to the NetBackup System Administrators Guide, Volume I.

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File system capacity

There must be ample file system space for NetBackup to record its loggingand/or catalog entries on each master server, media server, and client. If logging

or catalog entries should exhaust available file system space, NetBackup will

cease to function. Having the ability to increase the size of the file system via

volume management is recommended. The disk containing the NetBackup

master catalog should be protected with mirroring or RAID hardware or

software technology.

NetBackup catalog strategiesThe NetBackup catalog resides on the disk of the NetBackup master server. The

catalog consists of the following parts:

Image database: The image database contains information about what has

been backed up. It is by far the largest part of the catalog.

NetBackup data stored in relational databases: This includes the media and

volume data describing media usage and volume information which is used

during the backups.

NetBackup configuration files: Policy, schedule and other flat files used by

NetBackup.

For more information on the catalog, refer to Catalog Maintenance and

Performance Optimization in the NetBackup Administrator's Guide Volume 1.

The NetBackup catalogs on the master server tend to grow large over time and

eventually fail to fit on a single tape. Here is the layout of the first few directory

levels of the NetBackup catalogs on the master server:

Figure 2-3 Directory layout on master Server

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Catalog backup typesIn addition to the existing cold catalog backups (which require that no jobs be

running), NetBackup 6.0 introduces online hot catalog backups. These hot

catalog backups can be performed while other jobs are running.

Note: For NetBackup release 6.0 and beyond, it is recommended that you use

schedule-based, incremental hot catalog backups with periodic full backups as

your preferred catalog backup method.

Guidelines for managing the catalog NetBackup catalog pathnames (cold catalog backups)

/vault

/failure_history

/Master/client_1

/Media_server /client_n

/class_template

NBDB.db

EMM_DATA.db

EMM_INDEX.db

NBDB.log

BMRDB.db

BMRDB.log

BMR_DATA.db

BMR_INDEX.db

vxdbms.conf

/usr/openv/

/db/data

/error/class

Image databaseelational databasefiles

server.conf

databases.conf

/var/global

Configuration files

/client

/config

/images

/Netbackup/db

License key and authenticationinformation/var /Netbackup/vault

/jobs

/media

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When defining the file list, use absolute pathnames for the locations of the

NetBackup and Media Manager catalog paths and include the server name

in the path. This is in case the media server performing the backup ischanged.

Back up the catalog using online, hot catalog backup

This type of catalog backup is for highly active NetBackup environments in

which continual backup activity is occurring. It is considered an online, hot

method because it can be performed while regular backup activity is taking

place. This type of catalog is policy-based and can span more than one tape.

It also allows for incremental backups, which can significantly reducecatalog backup times for large catalogs.

Store the catalog on a separate file system

The NetBackup catalog can grow quickly depending on backup frequency,

retention periods, and the number of files being backed up. If you store the

NetBackup catalog data on its own file system, this ensures that other disk

resources, root file systems, and the operating system are not impacted by

the catalog growth. For information on how to move the catalog, refer to

Catalog compression on page 48.

Change the location of the NetBackup relational database files

The location of the NetBackup relational database files can be changed

and/or split into multiple directories for better performance. For example,

by placing the transaction log file, NBDB.log, on a physically separate drive,

you gain better protection against disk failure and increased efficiency in

writing to the log file. Refer to the procedure in the section Moving NBDB

Database Files After Installation in the NetBackup Relational Databaseappendix of the NetBackup System Administrators Guide, Volume I.

Delay to compress catalog

The default value for this parameter is 0, which means that NetBackup does

not compress the catalog. As your catalog increases in size, you may want to

use a value between 10 and 30 days for this parameter. When you restore

old backups, which requires looking at catalog files that have been

compressed, NetBackup automatically uncompresses the files as needed,with minimal performance impact. For information on how to compress the

catalog, refer to Catalog compression on page 48.

Catalog backup not finishing in the available windowIf your cold catalog backups are not finishing in the backup window, or hot

catalog backups are running a long time, here are some possible solutions:

Use catalog archiving. Catalog archiving reduces the size of online catalogdata by relocating the large catalog .f files to secondary storage. NetBackup

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