Re: Monitoring Memory and disks IOPS

[DrFranken <midrange@xxxxxxxxxxxx>]

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