This is one reason I am looking into some of the new, cheaper ATA-based
disk arrays.  98% of restores come from the last few versions, so if you
can size the diskpool large enough (and turn caching on) that you rarely
need to go to tape, restores scream.  Some of the initial prices I am
seeing are < $10k per TB.  It's not SSA, but for a diskpool it might be
fast enough.

-----Original Message-----
From: asr AT UFL DOT EDU 
Sent: Wednesday, October 30, 2002 10:15 PM
To: UFL.EDU.asr; VM.MARIST.EDU;.ADSM-L
Subject: Re: Tape drive recomendations


=> On Wed, 30 Oct 2002 16:42:14 -0600, "Coats, Jack"
<Jack.Coats AT BANKSTERLING DOT COM> said:

> From my fox hole, LTO works great, but in some ways it is 'to big'.  
> The spin time on the tapes is measured as about 3 minutes to rewind 
> and unmount a tape.  Meaning if you have to scan down a tape to 
> restore a file it can be a while.  Very fast tapes tend to be small, 
> so it is a real tradeoff.

> Speed of restore is starting to be a factor here and I have seen 
> several posts where that is becoming more of an issue at many sites.  
> But the architecture of TSM that makes it great, also gets in the way 
> of high speed restores, unless you have lots of slots in a large 
> library for a relatively small number of clients (co-location and/or 
> backup sets - for theses many smaller tapes might be better, but I 
> digress).


Our call on this is congealing: Use the LTO for less-often-read storage.
i.e.: copy pools.  If we can have primary pools on 3590s, we can get up
to 60G raw on the -K volumes.  That seems plenty at the moment.

We can use the 200G-raw (coming soon!) LTO volumes for copies, and read
from them correspondingly less often.

LTO drives are, at the very least, a cheap way to increase your drive
count.

- Allen S. Rout