From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU]On Behalf Of
Daniel Sparrman
> We have customers running OTG DiskXtender without problems. They have not
> experienced the problems you have described. Probably, the OTG client you
> have heard of have had some kind of configuration problems, as
> configuration and policy settings are normally the most difficult things
> to decide when implementing the DiskXtender client.

Yes, it is a booger to configure. I have talked to the OTG folks about
'wizarding' the setup process to make it more intuitive.

> We also have the OTG client in our own office, togheter with a MagStar
> 3575 tape library. Works good, no long retrieval times of data. A normal
> retrieve operation takes 10-15 seconds, which is in my opinion good. Our
> users can wait that long, as long as they now they will always be able to
> access their data.

The 3575 is an optimum library for HSM. It has fast mounting (about the
fastest in the industry today) and fast seeking. Its biggest drawback is the
lack of capacity.

> Another good thing with the DiskXtender client is that is shortens the
> restore times. If you move out 60% of you filedata from the
> fileserver, it
> means it's 60% less to restore if your server goes down. This is a very
> good way to secure that the server can be restored within a acceptable
> timelimit.

Good point! It's the best argument for HSM I've seen yet.

I actually don't see much use in HSM these days. Disk has gotten so
inexpensive that the cost per MB of tape and disk are getting comparable,
and HSM has the overhead of maintenance and equipment.

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