ADSM-L

Re: [ADSM-L] AW: TSM only reads from COPY1 during DB backup

2007-04-26 06:46:40
Subject: Re: [ADSM-L] AW: TSM only reads from COPY1 during DB backup
From: Richard Sims <rbs AT BU DOT EDU>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Thu, 26 Apr 2007 06:46:20 -0400
On Apr 26, 2007, at 4:02 AM, Salak Juraj wrote:

Hello Richard!

I understand your arguments are "either veracity or performance".
I believe the point you possibly oversee is that
if db reads were made from both sides of the mirror
then db backup performance would (with high probabilty) significantly rise
without harming database veracity.

However, this is theory only, as this is apparently not implemented in TSM DB, point.
Consequently both your and Orville´s conclusions are correct.

Combining reliability and speed in current designs would lead to
implementig both HW mirroring and TSM mirroring, at extra costs$.

Hi, Juraj -

Oh, I definitely appreciate the potential gains possible if all mirrors were employed for reads. (In the disks world, "the more arms, the better".) But, as we know, that is not TSM's current methodology.

There is the possibility of this situation changing, however, as pondered in paper
"A Close-up Look at Potential Future Enhancements"
available at http://tsm-symposium.oucs.ox.ac.uk/ 2005contributions.html . Perhaps this year's Oxford Symposium will air further momentum in this direction.

   Richard Sims

<Prev in Thread] Current Thread [Next in Thread>