Hi Paul. From bitter experience I have been saved by TSM mirroring on
nicely protected disks. I have had complete filesystems clobbered as
result of other hardware failures, nothing to do with the disks - have had
filesystems damaged on AIX  and also Windows. TSM mirroring is such a
superb, inexpensive protection against these other failures that I always
recommend TSM mirroring. It's also quite inexpensive give todays cost of
disk storage, including Shark. And yes, on a Shark I would create four
filesystems (/tsmdb1 /tsmdb2 /tsmlog1 /tsmlog2 - Windows an D: E: F: and
G: drive) so that the 1s and 2s (or the E: and G: drive) are in different
LSSs.

And yes, I wear belt and suspenders.

Joerg Pohlmann
604-535-0452




Paul Fielding <paul AT FIELDING DOT CA>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
2005-04-06 23:25
Please respond to
"ADSM: Dist Stor Manager"


To
ADSM-L AT VM.MARIST DOT EDU
cc

Subject
Re: Question on SETUP






I don't see the value in mirroring the db and logs if they're placed on
Shark disk.   The purpose of TSM's mirroring is to provide disk redundancy
in case of disk failure.   However, the Shark provides it for you.   Why
add
the extra overhead of software mirroring when the hardware does a valiant
job in the background. The Quck Start recommendation doesn't take into
account that your disk is already protected...

regards,

Paul

----- Original Message -----
From: "Jones, Eric J" <eric.j.jones AT LMCO DOT COM>
To: <ADSM-L AT VM.MARIST DOT EDU>
Sent: Wednesday, April 06, 2005 2:56 PM
Subject: [ADSM-L] Question on SETUP


> Good Afternoon.
> I was asked to setup a new TSM server 5.2.2 on a AIX 5.2 server.
> My question has to do with setting up the DB, LOG and DISKPOOL.
> On our current servers which run the same O/S and TSM version the DB,
LOG
> and DISKPOOL are mirrored.
> On the new system I'm setting up these are all going to reside on a IBM
> SAN(SHARK) which is all RAID.
> Is there any reason to mirror them since the mirror would be on the same
> set of drives(space was already allocated on a LUN)?
> I understand it's always good to mirror(protect DB, LOG, DISKPOOL) but
in
> this case I'd have to mirror to the same set of disk since I was only
> allocated a set of space to work.  In the TSM class it also recommended
> that you mirror for protection.
> I'm in the middle of reading the "Quick Start" for the second time and I
> see they recommend "Mirror your Database and recovery log for "Server
and
> storage pool protection".  I wanted to make sure there was not a
> performance issue or anything else.
>
> Have a Great Day,
> Eric Jones
>> *  eric.j.jones AT lmco DOT com
>> *:   607-751-4133
> Cell : 607-972-7621
>