We only back up 26 servers (NT, OS/2, Solaris, Linux, Mac) with one 3494
library and two 3590 drives. If we had collocation on our Copypool, it
would mean sending 26 tapes off-site every morning, even if most of them
had under a gig of data on them. All these tapes would then need to be
reclaimed (we set the reclamation threshold to 60%) keeping our two poor
tape drives permamnently busy. And, as we have a five day retention on our
pending volumes, this means a potential 100 odd tapes floating about that
we could be using.
We do collocate our Tapepool though to speed up restore times. Also, we
don't have the five day pending problem with the on-site tapes.
Farren - John Wiley & sons
Please respond to "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
To: ADSM-L AT VM.MARIST DOT EDU
cc:
Subject: Re: To Collate or Not to Collate? - UPDATE
It depends on the size of your library too. We don't Collocate and we
had a Disaster Recovery test and it was successful. We had time on our
hand too with the 36 hours time limits
David C. Pearson
IS Production Support Analyst
System & Network Service
Snohomish County PUD # 1
-----Original Message-----
From: Theresa Sarver [SMTP:tsarver.IFMC AT SDPS DOT ORG]
Sent: Wednesday, January 15, 2003 12:25 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: To Collate or Not to Collate? - UPDATE
Yikes! Okay, point(s) taken...Copypool set back to collate @ node level!
Thanks again;
Theresa
>>> Rene.Lambelet AT NESTLE DOT COM 01/15/03 02:18PM >>>
Hi, I fully agree. Specially after the experience of restoring one single
destroyed tape in primary pool that implied mounting 85 copy tapes!!
René LAMBELET
NESTEC SA
GLOBE - Global Business Excellence
Central Support Center
Information Technology
Av. Nestlé 55 CH-1800 Vevey (Switzerland)
tél +41 (0)21 924 35 43 fax +41 (0)21 703 30 17 local
UBS-Nestec, Bussigny
mailto:rene.lambelet AT nestle DOT com
This message is intended only for the use of the addressee
and may contain information that is privileged and confidential.
-----Original Message-----
From: Cook, Dwight E [mailto:DWIGHT.E.COOK AT SAIC DOT COM]
Sent: Wednesday, January 15, 2003 8:05 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: To Collate or Not to Collate? - UPDATE
Allen makes a critical implied statement of YOU MUST TEST YOUR RECOVERY
PLAN
!
If not and you have to use it and it doesn't go smooth...
Personally, I classify myself as probably being at the lowest place on the
earth... and even if something were to initially miss me, it would
undoubtedly/eventually settle on top of me! ! !
So... you request the test and state its requirement as to ensure
functionality.
If management says "no", make sure and put together a few things on what
~might~ go wrong like potentially 36 hours of nothing but tape mounts &
dismounts to restore just a single server (if like in Allen's case where
800
tapes were required)
Then make sure and save all the e-mails (print out and lock in a fireproof
safe) so you can mount a defense later ;-)
Dwight
-----Original Message-----
From: Allen Barth [mailto:allen.barth AT DB DOT COM]
Sent: Wednesday, January 15, 2003 12:31 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: To Collate or Not to Collate? - UPDATE
Glad you found it!
However, regarding the collocation=no issue on copypools....
Having done TSM DR recoveries at an offsite location a few times, let me
share my experiences. When I started with TSM I had one copypool with
colloc=no. We then did our first DR recovery test where my goal was to
recover the TSM server and ONE other AIX client. The base os (AIX) was to
restored via sysback, user filesystems via TSM. Originally this required
the ENTIRE copypool (800+ tapes back then) to be sent from the vault to
the DR location as TSM provides no command to see which vols would be
needed for a client node restore (hint, hint, IBM). Since then I've been
able to put an SQL query together to get that info but it takes quite a
while to execute. This trims down the number of tapes, but the number of
tapes was still quite large(100 +). Furthermore, the number of tape mount
requests during the restore was astronomical, as tapes were requested
multiple times. After re-thinking TSM and DR needs, I now have a
separated stgpool tree for unix data. Collocation is enabled for both
primary and copypools. At the last DR test, the number of tapes needed
from the vault was further reduced to around 40, and the restore process
took significantly less time. Let's not forget to factor in the time
required for physical tape processing (mount delay, seek time, rewind,
unload). This can add up to significant wall time.
Regards,
Al
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