I think orinally, it was because intersite SCSI/FC was impossible or too
expensive, while IP was "cheap". (Or maybe one TSM server had scsi tape
drives and a second did not.)
Virtual volumes are basically treating one TSM server as a "client" and
archiving to the other TSM server over IP.
 

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Keith Arbogast
Sent: Wednesday, August 22, 2007 4:35 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: [ADSM-L] Why virtual volumes?

Richard,
You asked thought provoking questions, but didn't answer mine. What is
the compelling reason to use virtual volumes? Offsite copypools and
certain restorability of the TSM database are essential. Thank you for
spotlighting those points. However, I can do those without virtual
volumes. Right? What circumstances make virtual volumes helpful,
preferable or necessary? TSM development designed and built them for a
reason. What is the reason?

This is not a rhetorical question. I am hoping someone will turn this
light bulb on for me.

With best wishes,
Keith Arbogast