Jeff Mikolai wrote:
>
> I am having a discussion about private volumes and performance issues. I
> have a relatively large account with 3 large databases. At one point in
> time, these three databases have been split across 3 private volumes. Now
> they all reside on one private volume. According to HP back when we did
> this, they said this would not be a performance issue. Could someone
> enlighten me on this issue a bit.

The always correct answer to performance questions is : 'it depends' :-)

but seriously there are 2 gotchas with what you described:

- if you id reduced the overall number of discs when changing from 3
  volume sets to only one you could have created an IO bottleneck.
  (that is unless you changed to faster disc and channels like from
  SE SCSI to F&W SCSI at the same time).
- If these databases are hitten by large numbers of user transactions,
  you may see the volume set master get very busy for XM (transaction
  manager) IOs. Previously you had 3 instances of XM logs one on each
  volume set, now with only one you might experience an IO bottleneck
  for the volume set master.

Unless these colleagues from HP did measure your IO rates on the old
setup before declaring this a non-issue, I am afraid you possibly did
not get the best advice.

Goetz.