On Sat, 26 Jan 2008 04:25:38 -0800 (PST), Polani wrote:

> I need one more advice from you , regarding VSCSI . I have just
> implemented a VIOS setup with one VIOS and a large number of client
> Lpars.
>
> I have used same VSCSI 9 (let's say vscsix ) on each client lpar to
> mapp disks for rootvg as well as disks for datavg.
>
> In my environment, rootvg is offcource on a scsi disk , being exported
> from VIOS servers , while datavg are on san disk ( again physically
> attached to FC adapters of VIOS servers).
>
> Question is that , what is best stretegy... Technically possible to
> use same vscsi for rootvg and datavg , but what is best practise ( and
> also from performance point of view)...
>
> I have searched manuals and redbook , nobody says about different
> VSCSI for rootvg and datavg ...
>
> For me , solution works fine and off course more complexity in
> management , if i retain with single vscsi strategy for each client
> lpar....
>
> Any comments or suggestions ...

I actually just posed this question to IBM. Their response was that
GENERALLY the only time you need more than 1 vscsi device is for
multipathing. Adding VSCSI devices is not a way to achieve improved
performance.