No. the RDAC and the SDD won't play nicely over the same HBA(s). The host
will only see on of the subsystems. I mistakenly did this and if I remember
the SDD took over and the host didn't see the RDAC volumes until I removed
the SDD volumes. Then I saw the RDAC volumes and remembered I forgot to
change the zoning.

Have you looked at the IBM SAN Volume Controller? You can have lots of
different storage subsystems behind the SVC and only need the SDD on the
hosts as the SVC presents a common front end to the hosts.

Bill Boyer
DSS, Inc.

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Gee, Norman
Sent: Sunday, December 21, 2008 3:19 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: 5.4 --> 6.0 (server)

What is your opinion of placing the DB2 database on a DS8300 or any
other high end SAN? (RAID 5 only, all 15K drives) parity write overhead.
Is it possible to access both a DS-4200 and a DS-8300 from the same pair
of FC cards?  Different multipath drivers.

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Remco Post
Sent: Sunday, December 21, 2008 3:26 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: 5.4 --> 6.0 (server)

On 21 dec 2008, at 08:56, Gee, Norman wrote:

> I guess with the rumor conversion to DB2, it would no longer be
> feasible
> to place the database on JBOD mirror by TSM.  The recommendation may
> be
> RAID 5 or 6 storage with fibre channel disks and not SATA disks. Am I
> close?

Well, even with current TSM levels I would only use 15kRPM disks in
RAID1. DB2 has no software mirroring, but your OS might very well do
the job for you, I know that Linux and AIX can, and I think recent
windows levels can do the same. RAID5 or RAID6 are great technologies,
but I don't believe that they mix very well with high performance
databases, not for TSM <= 5.5, and not for DB2 either.

SATA disks are only useful in very small TSM environments (up to a few
gig database), and well, that wont change much with DB2.

--
Met vriendelijke groeten/Kind regards,

Remco Post, PLCS
+31624821622