ZSYJKAA@WYOCDC1.BITNET (Jim Kirkpatrick 307 766-5303) (03/17/88)
A while ago I asked for people's opinions on backing up a large VAX system.
Here is the summary --
1. Nobody responded saying they don't do backups for users.
"I'd consider NOT backing up the disks an abdication of responsibility:
Backup services are among the most important things a central site can
provide in this era of ever-faster workstations." (Jerry Leichter)
2. Some sites are considering/using VHS videotape systems for backups.
As far as I can see, the advantages are cost, and space for the tapes,
but some quick calculating shows they are probably VERY slow compared
to a 120-ips 6250 9-track, so you take longer to do file saves (and,
if you shut down instead of trusting /IGNORE=INTERLOCK, that's bad).
3. Some people keep journal files, some print listings.
4. Most people do as I had originally proposed, more or less, taking
occasional fulls with various levels of incrementals.
5. Nobody claimed backing up a large VAX was easy; most pointed out straight
away that it is a BIG management problem, and usually not strictly
a technical problem (as when the college dean's son says he "must" be
able to run his job for 18 days straight).
6. Look into /FAST (though the manual really doesn't clearly explain when
it works and when it doesn't) and BUFFER=5 and make sure BACKUP has
plenty of memory and consider (carefully) NOCRC (though on our 8800s
CPU power is no problem).
7. If money is no problem, keep some disks as spares, and do fulls to them
and later copy to tape.
8. The DECUS VAX SIG and Large Systems SIG have been sponsoring sessions
on this topic. This should be a good source of info, if only I can
get to go to one.
I tried to respond to everybody who sent their ideas, but sometimes an
intermediate mailer bounced my reply. Thanks again to all. I will keep a
complete set of replies if anybody wants more nitty-gritty and/or examples,
though I won't be keeping it for too long.
Jim