[Ocfs-users] Re: ocfs performance question

[Sunil Mushran]

Well, you are the second person who has complained about
the performance of OCFS with the PERC controller.

Best option would be to contact DELL. We are in contact with
them... as in, they inform us of any issues they have with linux/ocfs
on their hardware. As we do not have this particular hardware inhouse,
all we can only speculate as to what the issue is.

Things to look for ==>

output of.... iostat 1
    Device:        tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
    dev8-1        2.00        36.00         1.00         36          1

This is just with 1 mounted ocfs volume and no processes touching it.
Notice the 2.00 tps... transfers per sec. If you see something like 37 
or so,
you are running into a known EL3 issue. (I think you are familiar with
this issue... qlogic folks referred you to the affine patch).

That's from the kernel end. From the device end, Dell should be able to
provide guidance.

Hope this helps.
Sunil

benwood1 at airmail.net wrote:

>Hello Sunil,
>
>I'm getting terrible performance out of an OCFS partition when attached
>using a Dell PERC 3/DC controller (w/ latest firmware) running RHEL 3.0. 
>Things are fine on an internal disk using the built-in SCSI controller on
>my Dell PowerEdge 2600, but when using the PERC everything falls apart. 
>Any ideas as to where to look for the source of this problem?  I noticed
>that the document "Linux Filesystem Performance Comparison for OLTP with
>Ext2, Ext3 ..." used a MegaRaid 1.73 so it's not like I'm using wacky
>hardware here...
>
>Many thanks!
>
>Best regards,
>Benjamin Wood
>General Dynamics
>
>  
>