The TSM Admin guide has the following info which I assume applies to client
backups:

Concurrent volume access
Disk Volumes: A volume can be accessed concurrently by different operations.
File Volumes: Only one operation can access the volume at a time.

So it depends on whether you are using device type disk or device type file
for your disk volumes.


-----Original Message-----
From: TSM_User [mailto:tsm_user AT YAHOO DOT COM]
Sent: Wednesday, November 17, 2004 12:49 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: TSM and SATA Disk Pools

Mark,
Where did you get the information about "each backup session
(remember a client could have multiple session) opens a volume for
its exclusive use".

I can't find any documentation anywhere to support this.  I have heard other
AIX admins make the same claim.  I have quite  few Windows TSM server that I
am sure have more client sessions sending data (consumer threads) then I
have disk pool volumes. I can't say I've ever run a q sess to see if the
number of nodes sessions in a SEND state are greater than the number of
volumes I have though.