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BACKING UP AND RESTORING DATA

Chapter 4

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CHAPTER OVERVIEW

• Describe the various types of hardware used to perform backups.

• Understand the difference between full, incremental, and differential backup jobs.

• List the capabilities of the Windows Server 2003 Backup program.

• Back up and restore an Active Directory database.

• Use volume shadow copies.

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BACKING UP DATA

• Why do we back up data?• Why do we need to back up data?

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BACKUP SOLUTION

• Backup hardware• Backup medium• Backup software• Data to be backed up

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BACKUP HARDWARE

• Capacity• Speed• Cost

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CD-ROM AND DVD-ROM

• CD• Inexpensive, widely supported• Capacity up to 650 MB

• DVD• Becoming less expensive• Less support than for CDs• Capacity can be over 4 GB

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CARTRIDGE DRIVES

• Proprietary technology• Zip (Up to 750-MB capacity)• Jaz (2-GB capacity)

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MAGNETIC TAPE DRIVES

• Use single or double spool magnetic cartridges

• Low cost per megabyte• Large capacity

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AUTOCHANGERS

• Reduce the need for manual intervention in backups

• Allow you to back up more data• Preserves investment in media

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SELECTING A DRIVE INTERFACE

• IDE• Inexpensive• Performance degrades drastically when

using more than one device per channel• SCSI

• Faster than IDE, more suited to writing continuous streams of data

• Might require additional host bus adapter (controller)

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BACKUP SOFTWARE

• Windows Server 2003 Backup• Third-party software

• Veritas Backup Exec• BrightStor ARCserve Backup

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TARGET SELECTION

• Anything that is to be backed up is considered a backup target, including:• Single file or folder• Entire drive• Entire system• Another system on the network

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USING TREE SELECTION

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USING FILTERS

• Filter on file creation date/time, size, or type • Allows you to perform customized backups• Can reduce the time needed to back up and

the amount of media required

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TYPE OF BACKUPS

Type Data Archive Flag

Full or Normal

All Clear

Incremental Modified since last full or incremental backup

Clear

Differential Modified since last full or incremental backup

Not Reset

Copy Backup – ignoring the archive flag

Not Reset

Daily Based on today’s date Not Reset

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BACKUP JOB TYPES: NORMAL

• Backs up all files• Clears the archive bit• Can require large data storage capacity

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BACKUP JOB TYPES: INCREMENTAL

• Backs up only files that have been modified or created since the last full or incremental backup

• Clears the archive bit• Can require considerably less storage space

than a normal backup• Faster to backup than differential, longer

restore

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BACKUP JOB TYPES: DIFFERENTIAL

• Backs up only files that have been modified or created since the last full or incremental backup

• Does not clear the archive bit• Can require considerably less storage space

than a normal backup• Longer to backup than incremental, faster

restore

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COPY JOBS AND DAILY JOBS

• Copy job• Backs up all files irrespective of archive bit

status• Does not change archive bit status

• Daily job• Backs up files based on today's date• Does not change archive bit status

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SPECIFYING A BACKUP JOB TYPE

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JOB SCHEDULING

• Allows backups to be performed during off-hours

• Reduces potential for administrative error

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MAINTAINING BACKUP LOGS

Detailed• Includes name and size of every file backed

upSummary• Errors, number of files backed up, amount

of data backed upNone• No logging, not even of error messages

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CATALOGING

• Allows backup software to keep track of what file is on what tape

• Eliminates the need for administrators to remember detailed information about the contents of a tape

• Can be stored on the system hosting the backup software or the tape

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MEDIA ROTATION

• Provides a method to retain backups for a given period

• Prevents overuse of mediaCommon rotation methods include:• Grandfather-Father-Son• Tower of Hanoi

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DEVICE CONFIGURATION

Tape formatting• Prepares a new or used tape for data storageTape erasing• Removes all data from the tapeTape retensioning• Mechanism to ensure that a tape has the proper

tensionCompression• Data compression that can often double the

amount of data written to a tape, with little or no performance impact

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PERFORMING RESTORES

• Complexity depends on backup cycle in use (full, incremental, differential).

• Amount of time depends on volume of data to be restored.

• Periodic restores should be performed to test integrity of backups.

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RESTORING FULL BACKUPS

• Easiest of all backup methods to restore• Restores latest full backup

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RESTORING FULL AND INCREMENTAL BACKUPS

• Restores the latest full backup• Restores incremental backups from oldest

to most recent• Number of restore steps depends on the

time since the last full backup

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RESTORING FULL AND DIFFERENTIAL BACKUPS

• Restores the latest full backup• Restores the latest differential backup• Only two restore steps are required

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DISASTER RECOVERY

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BACKUP SECURITY

• Create specific user account for backups• Password-protect tapes• Store and transport tapes securely

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USING WINDOWS SERVER 2003 BACKUP

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VOLUME SHADOW COPY

• Periodically saves copies of files• Can be used to restore previous versions of

a file• Available only in Windows Server 2003 and

Windows XP• Also used by Windows Server 2003 Backup

to make copies of open files

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ENABLING VOLUME SHADOW COPY

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BACKING UP ACTIVE DIRECTORY

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RESTORING ACTIVE DIRECTORY

• Can only be performed through Directory Services Restore Mode

Nonauthoritative restore• Used to rebuild a domain controller that has

been damaged, using the latest Active Directory information from your other domain controllers

Authoritative restore• Used when you want to recover Active

Directory objects that have been accidentally deleted using a System State backup

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SUMMARY

• A network backup solution consists of backup hardware, backup software, and a plan for using them.

• Incremental and differential backup jobs use the archive bit to determine what files need to be backed up.

• Network backup software enables you to back up data from computers anywhere on the network.

• Volume shadow copy enables users to access copies of files they have accidentally deleted or damaged.

• In Windows Server 2003 Backup, the System State object provides an easy way to back up Active Directory.

• Active Directory can be restored only through Directory Services Restore Mode.