[Lustre-discuss] performance issues in simple setup.

[murray]

Hi,
I have built a simple lustre setup. MDS and OSS are both on a Centos5
machine using the red hat lustre modified kernel
2.6.18-8.1.14.el5_lustre.1.6.4.1 running OFED-1.3.  Lustre is 1.6.4.3.

The client machine is Debian running the same kernel and OFED-1.3 and
lustre 1.6.4.3.

The MDT and OST are both single partitions on the the same disk (yes,
I know this is not optimal...)
The network uses Mellanox ConnectX HCAs running through a Voltaire
ISR2004 switch.

The basic RDMA setup seems to work in either direction:
murray at nasnu3:/slut$ ib_rdma_bw 192.168.3.50 (Lustre server)
5605: | port=18515 | ib_port=1 | size=65536 | tx_depth=100 |
iters=1000 | duplex=0 | cma=0 |
5605: Local address:  LID 0x07, QPN 0x22004e, PSN 0x323aa6 RKey
0x1a002800 VAddr 0x002aaaaaad6000
5605: Remote address: LID 0x05, QPN 0x8004f, PSN 0x67c28c, RKey
0x8002800 VAddr 0x002aaaab705000


5605: Bandwidth peak (#0 to #985): 1332.53 MB/sec
5605: Bandwidth average: 1332.47 MB/sec
5605: Service Demand peak (#0 to #985): 1462 cycles/KB
5605: Service Demand Avg  : 1462 cycles/KB

[murray at lusty bin]$ ib_rdma_bw 192.168.3.30 (Lustre client)
3845: | port=18515 | ib_port=1 | size=65536 | tx_depth=100 |
iters=1000 | duplex=0 | cma=0 |
3845: Local address:  LID 0x05, QPN 0xa004f, PSN 0x4f4712 RKey
0xa002800 VAddr 0x002aaaab705000
3845: Remote address: LID 0x07, QPN 0x24004e, PSN 0xa740c1, RKey
0x1c002800 VAddr 0x002aaaaaad6000


3845: Bandwidth peak (#0 to #956): 1533.5 MB/sec
3845: Bandwidth average: 1533.43 MB/sec
3845: Service Demand peak (#0 to #956): 1146 cycles/KB
3845: Service Demand Avg  : 1146 cycles/KB

Local disk speed on the Lustre server seems fine, as does speed when
the Lustre machine writes
to the Lustre mounted drive (50-80 MB/s).
[murray at lusty slut]$ dd if=/dev/zero of=foo bs=1048576 count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 13.5875 seconds, 79.0 MB/s

Performance of the client machine writing to the Lustre drive is poor
(12 MB/s)
murray at nasnu3:/slut$ mount -t lustre -l
192.168.3.50 at o2ib:/lusty on /slut type lustre (rw)

murray at nasnu3:/slut$ dd if=/dev/zero of=foo bs=1048576 count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 88.9857 seconds, 12.1 MB/s

Similar results from using Bonnie++ for the testing.

Any ideas as to what might be going on?
Thanks,
murray