=> On Wed, 11 Dec 2002 10:37:02 -0800, Gerald Wichmann <gwichman AT ZANTAZ DOT 
COM> said:


> Anyone have a particularly large HSM environment and been using it a while?
> I'm curious on any experiences with the product, good or bad. I would
> imagine there must be some people out there who need long term storage of
> infrequently accessed files and have considered it as a solution for that.


We don't have a "particularly large" HSM: We've got about 60GB migrated and
premigrated of system logs (trying to keep them forever) and another 60GB of
database load files.

Don't use shared memory transport.  TSM chokes itself on shared memory on a
regular, and rapid, basis.

Unfortunately, this means that even if you host the HSM filesystem on the TSM
server, you need to do network access through loopback.  D'oh, Sl'oh.  But for
HSM, you don't usually care about slow.

One interesting thing about HSM these days: Think about your incremental price
delta for new storage.

I think we quoted 18x36GB SSA, plus drawer, at $25K.  Raid5, hot spare, and
you've got $43/GB.

Take your new S frame at $21K, fill it with $50 K-tapes, pay $41K.

>From that make one primary, one copy stgpool.

Assume 1.5x compression across all data.

I make that $3.41/GB, if you _WRITE OFF_ such irrelevancies as, oh, the
server, the drives, etc.


Just keep those comaprisons in the back of your head as you evaluate possible
HSM applications.


- Allen S. Rout