Re: To Collate or Not to Collate?

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






Theresa Sarver <tsarver.IFMC AT SDPS DOT ORG>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
01/15/03 08:15 AM
Please respond to "ADSM: Dist Stor Manager"


        To:     ADSM-L AT VM.MARIST DOT EDU
        cc:
        Subject:        Re: To Collate or Not to Collate? - UPDATE


As embarassed as I am to admit this....I must confess that collation
turned out NOT to be the problem (with all my scratch tapes disappearing)
afterall.  Instead, it would appear that I inadvertantly (or carelessly -
whichever you prefer) deactiveated my 'Delete Volhist Admin Schedule' back
in August 2002.  After I deleted all the outdated volhist I went from 66
scratch to 285 scratch tapes.   Ahhh...to be yet again humbled by life....

But thanks to everyone for their responses I wouldn't have known to
check/set Collation=NO on the copy storage pool (as it was set to YES) if
it wasn't for you all.

So thanks again;
Theresa

>>> seay_pd AT NAPTHEON DOT COM 01/13/03 04:53PM >>>
How many tapes do you have in the tapepool?

Select count(*) from volumes where stgpool_name='TAPEPOOL'

How many drives do you have?

How many mounts are you getting during a stgpool backup?

Do you have maxpr specified on the stgpool backup?

What is the device class mount retention?

Are you using a maximum scratch number for tapepool or are you using
private
volumes?

Send a:
q stg tapepool f=d
q devclass [device class] f=d
q stg copypool f=d

Also, run this select to see if you have a lot of private volumes in the
library but not owned by any storage pool.  This happens when a tape is
not
labeled.

select volume_name from libvolumes where status='Private' and
libvolumes.volume_name not in (select volume_name from volumes) and
libvolumes.volume_name not in (select volume_name from volhistory where
type
in ('BACKUPFULL', 'BACKUPINCR', 'DBSNAPSHOT', 'EXPORT'))

With this information I may be able to help show that the collocation is
maybe not the total culprit.

Paul D. Seay, Jr.
Technical Specialist
Naptheon Inc.
757-688-8180


-----Original Message-----
From: Theresa Sarver [mailto:tsarver.IFMC AT SDPS DOT ORG]
Sent: Monday, January 13, 2003 4:06 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: To Collate or Not to Collate?


Hi All;

Environment:
SP Complex (7 wide nodes) running AIX 433 ML10
TSM 415
IBM 3494 (2-3590E drives)

When this was setup a couple years ago, they chose to enable collation, I
understand why - however, scratch tapes are now at a premium.  I would
like
to know if I disabled collation if that would help to free up some
tapes...and can it be disabled on the fly?  Or is my only solution to
start
trimming backups?

Also, our "tapepool to copypool" backup is now running over 24 hours.  Has
anyone else out there run into this problem before?  And if so - how did
you
get around it?  Oh, and I'll save you the time...Management refuses to buy
another drive.  - Time to get creative!

Thank you for your assistance;
Theresa