caspur / garr / cern / cnaf / csp new results from caspur storage lab andrei maslennikov caspur...

CASPUR / GARR / CERN / CNAF / CSP

New results from CASPUR Storage Lab

Andrei MaslennikovCASPUR Consortium

May 2003

A.Maslennikov - May 2003 - SLAB update

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Participated:

CASPUR : M.Goretti, A.Maslennikov(*), M.Mililotti,

G.Palumbo

ACAL FCS (UK) : N. Houghton

GARR : M.Carboni

CERN : M.Gug, G.Lee, R.Többicke, A.Van Praag

CNAF : P.P.Ricci, S.Zani

CSP Turin : R.Boraso

Nishan (UK) : S.Macfall

(*) Project Coordinator


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Sponsors:

E4 Computer : Loaned 6 SuperMicro servers (MBs and assembly) - excellent hardware quality and support – Italy

Intel : Donated 12 x 2.8 GHz Xeon CPUs

San Valley Systems : Loaned two SL1000 units - good remote CE support during tests

ACAL FCS / Nishan : Loaned two 4300 units - active participation in tests, excellent support


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Contents

• Goals

• Components and test setup

• Measurements: - SAN over WAN

- NAS protocols - IBM GPFS - Sistina GFS

• Final remarks

• Vendors’ contact info


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1. Feasibility study for a SAN-based Distributed Staging System

2. Comparison of the well-known NAS protocols on latest commodity hardware

3. Evaluation of the new versions of IBM GPFS and Sistina GFS as a possible underlying technology for a scalable NFS server.

Goals for these test series


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1. Feasibility study for a SAN-based Distributed Staging System

- Most of the large centers keep the bulk of the data on tapes and use some kind of disk caching (staging, HSM, etc) to access these data. - Sharing datastores between several centers is frequently requested, and this means that some kind of remote tape access mechanism should be implemented.

- Suppose now that your centre has implemented a tape<->disk migration system. And you have to extend your system to allow it to access the data dislocated on remote tape drives.

Let us see how this can be achieved.

Remote Staging


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Solution 1: To access a remote tape file, stage it on a remote disk, then copy it via network to the local disk. Local Site Remote Site

Remote Staging

Disk

Tape

Disk

Disadvantages:

- 2-step operation: more time is needed, harder to orchestrate- Wasted remote disk space


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Solution 2: Use a “tape server”: a process residing on a remote host that has access to the tape drive. The data are read remotely and then “piped” via network directly to the local disk. Local Site Remote Site

Remote Staging

Disadvantages:

- remote machine is needed- architecture is quite complex

Tape

Disk

TapeServer


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Solution 3: Access the remote tape drive as a native device on SAN. Use it then as if it is a local unit attached to one of your local data movers. Local Site Remote Site

Remote Staging

Benefits:

- Makes the staging software a lot simpler. Local field-tested solution applies.- Best performance guaranteed (provided the remote drive may be used locally at native speed)

Tape

Disk

Tape SAN


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“Verify whether FC tape drives may be used at native speeds over the WAN, using the SAN-over-WAN interconnection middleware” - In 2002, we had already tried to reach this goal. In particular, we used the CISCO 5420 iSCSI appliance to access an FC tape over the 400 km distance. We were able to write at the native speed of the drive, but the read performance was very poor.

- This year, we were able to assemble a setup which implements a symmetric SAN interconnection and hence used it to repeat these tests.

Remote Staging


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2. Benchmark the well-known NAS protocols on a modern commodity hardware.

- These tests we do on a regular basis, as we wish to know what performance we may currently count on, and how the different protocols compare on the same hardware base.

- Our test setup was visibly more powerful than that of the last year, so we were expecting to obtain better numbers.

- We were comparing two remote copy protocols: RFIO and Atrans (cacheless AFS), and two protocols that provide the transparent file access: NFS and AFS.

NAS protocols


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3. Evaluate the new versions of IBM GPFS and Sistina GFS as a possible underlying technology for a scalable NFS server.

- In 2002, we have already tried both GPFS and GFS.

- GFS 5.0 has shown interesting performance figures, but we have observed several issues with it: unbalanced perfomance in case of multiple clients, exponential increase of load on the lock server with increasing number of clients.

- GPFS 1.2 was showing a poor performance in case of concurrent writing on several storage nodes.

- We used GFS 5.1.1 and GPFS 1.3.0-2 during this test session.

Goal 3


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- High-end Linux units for both servers and clients 6x SuperMicro Superserver 7042M-6 and 2x HP Proliant DL380 with:

2 CPUs Pentium IV Xeon 2.8GHz SysKonnect 9843 Gigabit Ethernet NIC (fibre)

Qlogic QLA2300 2Gbit Fibre Channel HBA Myrinet HBA

- Disk systems 4x Infortrend IFT-6300 IDE-to-FC arrays:

12 x Maxtor DiamondMax Plus 9 200 GB IDE disks (7200 rpm) Dual Fibre Channel outlet at 2 Gbit

Cache: 256 MB

Components


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- Tape drives 4x LTO/FC (IBM Ultrium 3580)

- Network 12-port NPI Keystone GE switch (fibre)

28-port Dell 5224 GE switches (fibre / copper)

Myricom Myrinet 8-port switch

Fast geographical link (Rome-Bologna, 400km), with guaranteed throughput of 1 Gbit.

- SAN Brocade 2400, 2800 (1Gbit) and 3800 (2Gbit) switches

SAN Valley Systems SL1000 IP-SAN Gateway

Nishan IPS 4300 multiprotocol IP Storage Switch

Components -2


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New devices

We were loaned two new objects, one from San Valley Systems, and one from Nishan Systems. Both units provide the SAN-over-IP interconnect function, and are suitable for wide-area SAN connectivity.

Let me give some more detail of both units.

Components -3

16A.Maslennikov - May 2003 - SLAB update

San Valley Systems IP-SAN Gateway SL-700 / SL-1000

- 1 or 4 wirespeed Fibre Channel -to- Gigabit Ethernet channels- Uses UDP and hence delegates to the application the handling of a network outage- Easy in configuration- Allows for the fine-grained traffic shaping (step size 200 Kbit, 1Gb/s to 1Mb/s) and QoS - Connecting two SANs over IP with a pair of SL1000 units is in all aspects equivalent - to the case when these two SANs are connected with a simple fibre cable - Approximate cost: 20 KUSD/unit (SL-700, 1 channel)- 30 KUSD/unit (SL-1000, 4 channels)

- Recommended number of units per site: 1-

17A.Maslennikov - May 2003 - SLAB update

Nishan IPS 3300/4300 multiprotocol IP Storage Switch

- 2 or 4 wirespeed iFCP ports for SAN interconnection over IP- Uses TCP and is capable to seamlessly handle the network outages- Allows for traffic shaping at predefined bandwidth (8 steps,1Gbit- 10Mbit) and QoS- Impements an intelligent router function: allows to interconnect multiple fabrics from different vendors and makes them look as a single SAN- When interconnecting two or more separately managed SANs, maintains their independent administration - Approximate cost: 33 KUSD/unit (6 universal FC/GE ports + 2 iFCP ports - IPS 3300) 48 KUSD/unit (12 universal FC/GE ports + 4 iFCP ports - IPS 4300)

- Recommended number of units per site: 2 (to provide redundant routing)


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CASPUR Storage Lab

HP DL380 Bologna Gigabit IP (Bologna)FC SAN (Bologna)

IPS 4300

SL1000

HP DL380 Rome

SM 7042M-6

SM 7042M-6

Myrinet

Gigabit IP (Rome)SM 7042M-6

SM 7042M-6

SM 7042M-6

SM 7042M-6 Disks

Tapes

FC SAN (Rome)

IPS 4300SL1000

1 Gbit WAN, 400km


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Series 1: accessing remote SAN devices

Disks

Tapes

FC SAN (Rome) IPS 4300

SL1000

FC SAN (Bologna) IPS 4300

SL1000

1 Gbit WAN, 400km

HP DL380 Bologna

HP DL380 Rome


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We were able to operate at the wire speed (100 MB/sec over400 km distance) with both SL-1000 and ISP 4300 units!

- Both middleware devices worked fairly well

- We were able to operate with tape drives at the drive native speed (R and W): 15 MB/sec in case of LTO and 25 MB/sec in case of other faster drive

- In case of disk devices we have observed a small (5%) loss of performance on writes and a more visible (up to 12%) loss on reads, on both units. - Several powerful devices grab the whole available bandwidth of the GigE

- in case of Nishan (TCP-based SAN interconnection) we have witnessed a successful job completion after an emulated 1-minute network outage

Conclusion: Distributed Staging based on a direct tape drive access is POSSIBLE.

Series 1 - results


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Series 2 – Comparison of NAS protocols

Server ClientGigabit Ethernet

W: 78 MB/secR: 123 MB/sec

Infortrend IFT6300FC 2 Gbit


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Some settings: - Kernels on server: 2.4.18-27 (RedHat 7.3, 8.0) - Kernel on client: 2.4.20-9 (RedHat 9) - AFS : cache was set up on ramdisk (400MB) - used ext2 filesystem on server

Problems encountered: - Poor array performance on reads with kernel 2.4.20-9

Series 2 - details


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Write tests: - Measured average time needed to transfer 20 x 1.9 GB from memory on the client to the disk of the file server and vice versa including the time needed to run “sync” command on both client and the server at the end of operation: 20 x {dd if=/dev/zero of=<filename on server> bs=1000k count=1900}

T=Tdd + max(Tsyncclient, Tsyncserver)

Read tests: - Measured average time needed to transfer 20 x 1.9 GB files from a disk on the server to the memory on the client (output directly to /dev/null ).

Because of the large number of files in use and the file size comparable with available RAM on both client and server machines, caching effects were negligible.

Series 2 – more detail


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Series 2- current results (MB/sec) [SM 7042 - 2GB RAM on server and client]

Write Read

Pure disk 78 123

RFIO 78 111

NFS 77 80

AFS cacheless(Atrans) 70 59

AFS 48 30


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Series 3a – IBM GPFS

4 x IFT 6300 disk arrays

SM 7042M-6

SM 7042M-6

SM 7042M-6

SM7042M-6

FC SANNFS

Myrinet


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GPFS installation: - GPFS version 1.3.0-2 - Kernel 2.4.18-27.8.0smp - Myrinet as server interconnection network - All nodes see all disks (NSDs)

What was measured: 1) Read and Write transfer rates (memory<->GPFS file system) for large files 2) Read and Write rates (memory on NFS client<->GPFS exported via NFS)

Series 3a - details


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Series 3a – GPFS native (MB/sec)

R / W speed for a single disk array: 123 / 78

Read Write

1 node 96 117

2 nodes 135 127

3 nodes 157 122


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Series 3a – GPFS exported via NFS (MB/sec)

1 node exporting

2 nodes exporting

3 nodes exporting3 clients 6 clients 9 clients

Read 84 113 120

Write 107 106 106

1 client 2 clients 3 clients 9 clients

Read 35 44 44 44

Write 55 73 83 88

2 clients 4 clients 6 clients

Read 60 72 85

Write 90 106 106


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Series 3b – Sistina GFS

4 x IFT 6300 disk arrays

SM 7042M-6

SM 7042M-6

SM 7042M-6

SM7042M-6

FC SAN

SM7042M-6

NFS

Lock Server


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GFS installation: - GFS version 5.1.1 - Kernel: SMP 2.4.18-27.8.0.gfs (may be downloaded from Sistina together with the trial distribution), includes all the required drivers.

Problems encountered: - Kernel-based NFS daemon does not work well on GFS nodes (I/O ends in error). Sistina is aware of the bug and is working on that using our setup. We hence used user space NFSD in these tests, it was quite stable.

What was measured: 1) Read and Write transfer rates (memory<->GFS file system) for large files 2) Same for the case (memory on NFS client<->GFS exported via NFS)

Series 3b - details


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Series 3b – GFS native (MB/sec)

NB: - Out of 5 nodes: 1 node was running the lock server process 4 nodes were doing only I/O

Read Write

1 client 122 156

2 clients 230 245

3 clients 291 297

4 clients 330 300

R / W speed for a single disk array: 123 / 78


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Series 3b – GFS exported via NFS (MB/sec)

8 clients

Read 250

Write 236

1 client 2 clients 4 clients 8 clients

Read 54 67 78 93

Write 56 64 64 61

3 clients 6 clients 9 clients

Read 145 194 207

Write 164 190 185

1 node exporting

NB: - User space NFSD was used

3 nodes exporting

4 nodes exporting


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- We are proceeding with the test program. Currently under test: new middleware from CISCO, new tape drive from Sony. We are expecting also a new iSCSI appliance from HP, and an LTO2 drive.

- We are open for any collaboration.

Final remarks


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- Supermicro servers for Italy E4 Computer Vincenzo Nuti - [email protected]

- FC over IP San Valley Systems John McCormack - [email protected]

Nishan Systems Stephen Macfall - [email protected]

ACAL FCS Nigel Houghton - [email protected]

Vendors’ contact info

caspur / garr / cern / cnaf / csp new results from caspur storage lab andrei maslennikov caspur...

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