Just a quick follow on to the last post. If you try to use native IB support with GPFS instead of the IP over IB you need to set the verbsRdma to enabled. You also need to set the rdma device to use with the verbsPort setting. If you get the following error in /var/mfms/gen/mmfslog then you didn’t properly set the verbsPort
VERBS RDMA starting.
VERBS RDMA library libibverbs.so (version >= 1.1) loaded and initialized.
VERBS RDMA library libibverbs.so unloaded.
VERBS RDMA failed to start, no verbsPorts defined.
Here is what I used for our single port HBA Infiniband setup.
mmchconfig verbsPorts=”ib0/1″
mmchconfig verbsRdma=enable
Then looking at my configuration I now show things correctly
[root@topaz-m1 ~]# mmlsconfig
Configuration data for cluster aaa.bbb.navy.mil:
—————————————————-
clusterName aaa.bbb.navy.mil
clusterId 72452797724XXXXXXXX
clusterType lc
autoload no
minReleaseLevel 3.2.1.5
dmapiFileHandleSize 32
dataStructureDump /scratch/root/GPFS_Dump
maxblocksize 512K
maxFilesToCache 7000
maxMBpS 2048
maxStatCache 28000
pagepool 512M
verbsPorts ib0/1
verbsRdma enableFile systems in cluster aaa.bbb.navy.mil:
———————————————
/dev/gpfs_a
/dev/gpfs_b
/dev/gpfs_c
/dev/gpfs_d
Success. I am now running gpfs natively across Infiniband with Linux. Much better performance this way.
Our basic configuration in case you are wondering.
40 Dell 1950 and 2950 nodes.
- 1 head node 2950
- 4 I/O 2950 nodes with HBA’s and HCA’s
- 32 Compute nodes HBA’s
- several misc nodes with HBA’s
Qlogic single port HBA’s
Redhat Enterprise Server 5.1
GPFS 3.2.1.9
DDN 9900


3 comments
Comments feed for this article
March 8, 2009 at 2:54 AM
John Leidel
Wicked cool Rich! Glad you got it working!
September 3, 2009 at 10:52 PM
Brian McNally
Thanks for the write-up. I just got RDMA over IB working today. One thing that took me some time to figure out was what my IB interface was called. The ibv_devinfo command will tell you that:
…
hca_id: mlx4_0
…
September 16, 2010 at 2:16 AM
Kris Howard
Rich. I love you. Thanks for the info when I need it! You da man!