Re: Monitoring Memory and disks IOPS

Have to agree with almost everything Rob says here. On the performance of VIOS with internal disks however I understand that has been corrected with PTFs to i and patches to VIOS. Even with that I would still use IBM i to hosts the disks if you are using internal storage. Hands down easier to manage by a Wiiiiiide margin.

- Larry "DrFranken" Bolhuis

www.frankeni.com
www.iDevCloud.com
www.iInTheCloud.com

On 3/12/2015 9:59 AM, rob@xxxxxxxxx wrote:

Are you using SAN storage, or disks internal to your Power 8? If using
internal disks then do NOT let VIOS control those disks. Instead, set up
a 7th lpar of IBM i as a "host" lpar and have that lpar control the disks.
You can still use the VIOS to share tape or ethernet. I've tried it both
ways and ended up pretty much scratching and starting over because the
VIOS control of internal disks was so horrible on performance.

If using external SAN storage then let VIOS control the disks.

A decent BP (business partner) should be able to get you a temporary copy
of MPG or something and analyze the disk IOP's for you. WRKDSKSTS
probably doesn't have what you are asking for.

We have three Power 8's. All three have 2 redundant VIOS lpars and 1
hosting lpar of IBM i for disks.
Two "hosts" host (4 lpars of IBM i and one of AIX) each.
One hosts just 3 lpars of IBM i.

Rob Berendt