rootvg with SDD?

[Tom Kunkel]

I know it is possible to use plain Shark FC disk for rootvg. I wonder
if anyone has tried this and what happened with the SDD devices? Any
feedback appreciated!

[Jan Willem de Lange]

Tom,
You can use the hdiskx as a bootable device, but you can NOT use the
vpath (or EMC hdiskpower) as boot device, because at boottime your
(SDD) drivers are not loaded yet. To boot from a vpath you will need
firmware/microcode, I don't know if IBM has provided that at the
moment
Jan W.

"Tom Kunkel" <kunkelt@yahoo.com> schreef in bericht
news:6714cdb9.0309080208.1b593b2c@posting.google.c om...

> I know it is possible to use plain Shark FC disk for rootvg. I

wonder

> if anyone has tried this and what happened with the SDD devices? Any
> feedback appreciated!

[F. Michael Orr]

"Jan Willem de Lange" <jan.willem.de.lange@freeler.nl> wrote in message
news:1063025728.360944@evisp-news-01.ops.asmr-01.energis-idc.net...

> Tom,
> You can use the hdiskx as a bootable device, but you can NOT use the
> vpath (or EMC hdiskpower) as boot device, because at boottime your
> (SDD) drivers are not loaded yet. To boot from a vpath you will need
> firmware/microcode, I don't know if IBM has provided that at the
> moment
> Jan W.
>
> "Tom Kunkel" <kunkelt@yahoo.com> schreef in bericht
> news:6714cdb9.0309080208.1b593b2c@posting.google.c om...

> > I know it is possible to use plain Shark FC disk for rootvg. I

> wonder

> > if anyone has tried this and what happened with the SDD devices? Any
> > feedback appreciated!

>
>

The SDD User's Guide (SC26-7540) very specifically mentions that this is not
supported. Neither are paging spaces.

[Brian W. Hart]

[email]jan.willem.de.lange@freeler.nl[/email] wrote:

>Tom,
>You can use the hdiskx as a bootable device, but you can NOT use the
>vpath (or EMC hdiskpower) as boot device, because at boottime your
>(SDD) drivers are not loaded yet. To boot from a vpath you will need
>firmware/microcode, I don't know if IBM has provided that at the
>moment

This is a bit late, but..

You can't boot from a vpath or hdiskpower as a boot device, but more
should be said... Boot from a Fibre Channel attached hdisk is OK, but
boot from a _multi-pathed_ hdisk is no good _unless it's an MPIO hdisk_.

That is, basically, if you see multiple hdisks that correspond to the
same volume, then you shouldn't boot from them. You might get it work,
but you may experience problems with reservations, mksysb restore,
migration, etc.

Boot from a single-pathed FC hdisk should just fine (assuming it's a
supported disk type, blah blah blah). And SDD now ships the
"querysn" command to allow you to tell SDD not to build the "extra"
vpath for your boot volumes.

MPIO is now available for Fibre Channel disks in AIX 5.2 ML1. I
think Fibre Channel boot will become more useful as disk vendors
begin to announce support for and ship MPIO-aware device support.

Regards,
brian