I at one time had my primary backup pool go into a VTS.  Mine is a 3494-B18,
older model.   TSM likes to append to tape volumes until they are full. The
recall process to stage a virtual volume from tape back to disk cache will
take from 4 to 6 minutes and then TSM will start appending the tape and then
it is written back to tape back end.  When you start tape reclamation, it
will take 4 to 6 minutes to load each 800 MB volume that needs to be
reclaim.  Tape reclamation is a real pain,  at one time I was reclaiming 50
volume daily.  I had 1200 virtual volumes before I decided to convert it all
to native 3590 cartridges.

I backup my database to VTS, but my offsite I take a DB SNAPSHOT to a 3590
cartridge.

-----Original Message-----
From: Steve Harris [mailto:Steve_Harris AT HEALTH.QLD.GOV DOT AU]
Sent: Thursday, October 14, 2004 4:38 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: Changes to Tape Management hardware in Data Center

Shannon,

What was the reason for purchasing the VTL?  I'd surmise it is probably to
do tape consolidation on your mainframe operations.

*caveat! I have not actually used a 3494 VTL*

Past posts here have indicated that TSM is not a good fit for the VTL
because of the overhead of staging data that will only be used once and then
destaged.

I'd have to question why there is a perceived need to keep the archives in
3480 format.  I can think of no reason to when native 3590s are available,
other than a larger number of available drives.  Sure, copy them over that
way at conversion time if there is a co-existence issue with the new and old
libraries, but new ones, nah.

I understand that the VTL can be logically split into a native library and a
VTL.  I'd suggest for TSM that you use the native library. See the other
posts earlier today about how to migrate to the new media.

Regards

Steve

Steve Harris
AIX and TSM Admin - ex mainframer 1980-1997
Queensland Health, Brisbane Australia


I do have a question here about backing up the TSM database. Will it be
possible to do some kind of DB Backup to the VTS and still keep my DB
Series that is going offsite?

        2.      In addition to the VTS and our current Magstar, we are
adding a 3494 -D14 and a 3494 -D12, that have a total of (6) 3590E drives.
As with the Magstar, it will use the 3590J cartridges but will they should
hold more data because of               the difference between the Magstar
3590B drives vs. the 3590E drives on the new ATL.  The following is the
how             this hardware change will have an effect on our TSM backup
environment,