Both can be used, both have advantages and disadvantages.

TSM development is focusing efforts on File Device Class.

Search the archives for some info on which to use
(http://msgs.adsm.org/cgi-bin/get/adsm0406/106.html)

Check out the 5.2 Admin guide - it has a nice table comparing disk vs file.

The biggest drawbacks of disk to me are - no reclamation of aggregates and
no multi-session restore. (See the comparisons for more).

-----Original Message-----
From: Robert R Price [mailto:rprice28 AT CSC DOT COM]
Sent: July 30, 2004 9:32 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: D2D vs. tape backups with TSM?

I know that I must be missing something here, but can someone explain why
this D2D backup scheme utilizes what I assume to be the sequential FILE
device type?  Why not just use the (random) DISK storage pool type.  This
would eliminate any co-location issues, reclaims and not waste ANY disk
space with deleted files?  Would someone enlighten me?