--> ... in these days where disk space is not much more expensive than tape 
space.
I would disagree on part. LTO is sligthly better than disks when measured
I would disagree on part. LTO is sligthly better than disks when measured
in TB/sq.m. but does not require those many kVAs disks need. Disks require
about 30W/drive + some extra for controllers, etc. Also this electricity
transforms into heat. So you need initial investment for big UPSes and
conditioners and they also have to be counted for floorspace. EMC
Symmetrix or IBM ESS require 20-30kVA UPS and also corresponding
batteries.
Thus again - it depends.

Zlatko Krastev
IT Consultant




Please respond to "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
Sent by:        "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
To:     ADSM-L AT VM.MARIST DOT EDU
cc:

Subject:        Re: opinion on AIT vs LTO and 3570 tape technology?

From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU]On Behalf Of
Lisa Cabanas
> I had briefly thought about HSM, but the enormous number of files and
> directories makes it sound like a really bad idea to me.  Any thoughts?

The HSM issue is not a matter of the number of files and directories, but
rather an issue of frequency of access. If the files are generated and
then
rarely accessed, HSM would make sense, given if the following is true:

1. The customer is *really* tight on disk space, and
2. The files are infrequently accessed, but need to be immediately
available.

HSM is a more complex issue if you're dealing with Windows client boxes.
You'll have to look at a solution like OTG DiskXtender for non-UNIX
clients.

HSM actually doesn't make a lot of sense, in these days where disk space
is
not much more expensive than tape space.

--
Mark Stapleton (stapleton AT berbee DOT com)
Mark Stapleton (stapleton AT berbee DOT com)
Certified TSM consultant
Certified AIX system engineer
MSCE