ADSM-L

Re: size of active vs. inactive?

2004-11-30 10:38:00
Subject: Re: size of active vs. inactive?
From: Richard Sims <rbs AT BU DOT EDU>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Tue, 30 Nov 2004 10:36:27 -0500
On Nov 30, 2004, at 9:58 AM, Johnson, Milton wrote:

...Needless to say, I disagree with the statement that TSM doesn't
appear
to be a good fit for a VTL.  Remember a VTL is just a library that can
mount/unmount a tape in less than one second and read/write to the tape
at disk speeds.  Why wouldn't TSM work well with a library on
steroids? ...

Thanks for sharing your experience with VTL in a TSM environment:
it's helpful to have the perspective of experience.
As we've seen in past tape vs. disk discussions, though, don't regard
"disk speed" as some kind of ultimate data processing I/O attainment:
high performance tape technologies streaming to sequential media can
in many cases out-pace disk throughput.  It is in mounting and tape
positioning that tape is a poor performer relative to disk, where one
can wait a minute or more before I/O can proceed.  That's were VTL
shines.

   Richard Sims