[geeks] Veritas VxFS and Solaris 9 and MySQL - tuning?

[Jonathan J. M. Katz]

On Tue, Oct 20, 2009 at 9:28 AM, Patrick Giagnocavo <patrick at zill.net> wrote:
> Solaris 9
> Veritas VxFS v4.0
> MySQL 5.x

Is vxstat showing IO contention?

How many paths to the disk (internal, external?) DMP is licensed
separately, so they may or may not be using that, but may not have
MPXIO (scsi_vhci) turned on.

Are they using directIO (QuickIO, since it is vxfs.) It is a
mount-time option. If on, turn it off. If off, turn it on.

I know with Oracle tuning there is a "buffer block size" .. I'm sure
MySQL has something similar. It sometimes helps to make the filesystem
formatted with the same block size. For vxfs this can be problematic,
as its default size is 2k, and Oracle's is 8k. So doing your mkfs_vxfs
with -b 8192 can help Oracle performance.

What's the shared memory status? Do you have enough buffers. ipcs can
help with that.

Other things that come to mind; if there are significant reads on the
DB, it helps to make sure indexes are on a different spindle than
data, etc.

Good luck.