In general, discouraged. What you want instead is big, native-mode RAID
arrays, configured as disks using devtype=file, not as virtual tapes.
You get a lot more flexibility and a lot less complexity, compared to a
VTL. TSM even does the backup-to-tape function better. (copy pools) The
VTL software layer is unnecessary overhead, and unnecessary
administrator effort, in the case of TSM. You'll save money, too.

If the VTL salesman tries to convince you that there are limitations in
TSM that make a VTL necessary, he's probably talking about the
one-filesystem limitation for devtype=file, which was removed in TSM
5.3. Since 5.3, the last reason to prefer a VTL is gone. Took me 45
minutes with a very determined EMC salesman who thought he knew all
about TSM, and filled my email inbox with PDF white papers to prove it,
to convince him that I wanted to see a plain ordinary EMC disk box, not
one dressed up as a VTL.

Roger Deschner      University of Illinois at Chicago     rogerd AT uic DOT edu
= "Things are more like they are now than they have ever been before." =
======================== --Dwight D. Eisenhower ========================

>-----Original Message-----
>From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
>Gill, Geoffrey L.
>Sent: 06 February 2007 02:15
>To: ADSM-L AT VM.MARIST DOT EDU
>Subject: [ADSM-L] VTL's (looking for info)
>
>Does anyone have a doc or a link to anything that discusses the pro's
>and con's of a VTL?
>
>
>Geoff Gill
>TSM Administrator
>PeopleSoft Sr. Systems Administrator
>SAIC M/S-G1b
>(858)826-4062
>Email: geoffrey.l.gill AT saic DOT com
>