[Linux-cluster] slow I/O on v7000 SAN

[Michael Bubb]

Thank yo uBob - looks interesting.

We are:

[root at ny7blade01 ~]# uname -a
Linux ny7blade01 2.6.32-131.17.1.el6.x86_64 #1 SMP Thu Sep 29 10:24:25
EDT 2011 x86_64 x86_64 x86_64 GNU/Linux


That bug looks limited to RHEL 5.x - would it affect us?



On 11/16/2011 11:57 AM, Bob Peterson wrote:
> ----- Original Message -----
> | Hello -
> | 
> | We are experiencing extreme I/O slowness on a gfs2 volume on a SAN.
> | 
> | We have a:
> | 
> | Netezza TF24
> | IBM V7000 SAN
> | IBM Bladecenter with 3 HS22 blades
> | Stand alone HP DL380 G7 server
> | 
> | 
> | The 3 blades and the HP DL380 are clustered using RHEL 6.1 and
> | clustersuite 5.5.
> | 
> | We have 2 clustered volumes on different storage pools (one has 10k
> | drives the other 7.2k).
> | 
> | We have an internal test that reads a large file (950G) using fopen
> | and
> | memmap. On a standalone server in a datacenter (Ubuntu Raid 5 10k
> | disks)
> | the tests take approximately 75seconds to run.
> | 
> | On the blades the test takes 300 - 350 seconds.
> | 
> | I have been looking at the cluster conf; any gfs tuning I can find. I
> | am
> | not really sure what I should post here?
> | 
> | yrs
> | 
> | Michael
> | 
> | --
> | 
> | 
> | Michael Bubb
> | System Administrator
> Hi Michael,
> 
> It sounds like you probably ran into our "Large File Allocate" bug.
> This is solved in recent kernels, including 5.7.z, 5.8, 6.3, etc.
> More info here:
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=683155
> 
> Regards,
> 
> Bob Peterson
> Red Hat File Systems
> 
> --
> Linux-cluster mailing list
> Linux-cluster at redhat.com
> https://www.redhat.com/mailman/listinfo/linux-cluster

-- 


Michael Bubb
System Administrator
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