Date:         Fri, 12 Jul 2002 09:04:39 -0700
Reply-To:     Cassell.David@EPAMAIL.EPA.GOV
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "David L. Cassell" <Cassell.David@EPAMAIL.EPA.GOV>
Subject:      Re: Off topic: Solaris hierarchical storage
Content-type: text/plain; charset=us-ascii

pudding_man@lycos.com replied [in part]:
> Restore from disk is relatively transparent to the user.
> Restore from tape can be anything _but_ transparent to
> an interactive user. It often freezes the user's
> process while a tape mount request is issued. Even if
> a tape drive is available, this can result in a
> sizable wait. One might assume that HSM would be
> configured to gobble up only large unaccessed files,
> but I've seen it usurp little parm files, tiny
> flat files, PDS's using maybe 2 tracks (about 115k),
> etc.
>
> In fact, there are probably some folks out there that
> feel that "DFHSM does more to bugger productivity than
> any other software product in the mainframe environment".
> I myself have had to write batch programs to restore
> datasets so users could run interactive applications
> unhindered.

Good point.  When a hierarchical-storage program guarantees
"30-minute response" as their maximum wait-time, you have to
consider how many users would consider that to be 'transparent'.
[Is that a :-) or a :-( statement?]

David
--
David Cassell, CSC
Cassell.David@epa.gov
Senior computing specialist
mathematical statistician