If TSM moves data from a (disk) dedup pool to tape, TSM has to un-dedup the 
data as it reads it and sends it to tape.


-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Dan Haufer
Sent: Thursday, June 12, 2014 8:03 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: [ADSM-L] TSM and VTL Deduplication

Greetings,

We are trying to evaluate the  possibility of introducing deduplication into 
our backups. Our initial deployment will be based on quadstor vtl 
http://www.quadstor.com/virtual-tape-library.html but at the same time we are 
trying to understand the TSM deduplication feature. Could anyone tell me what 
the following means from the TSM deduplication FAQ  
https://www.ibm.com/developerworks/community/wikis/home?lang=en#!/wiki/Tivoli%20Storage%20Manager/page/Deduplication%20FAQ

--
 (Q4) When should I consider using TSM deduplication?

    Consider using TSM deduplication when the following conditions apply:
        You plan to use a disk-only backup solution (your primary backup 
storage pool will remain on disk).
--

I understand why the backup pool should be a disk pool, but the "disk-only 
backup solution" confuses me. Does tape migration cause any effects ?

TSM Server version v6.3.3
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