🚀 go-pugleaf

rmilner@zia.aoc.nrao.edu (Ruth Milner) writes:

>So, before I go call Legato and order it :-), can you tell us a bit more:
>
>   - how much (just roughly) did it cost?
>   - did you have to pay by the number of systems being backed up, the 
>     number of tape drives you will use with it, or just a single licence,
>     say for the system you will be initiating all of this from?

	The DECNsr product (built on Legato's networker) is licensed based
on one server and then a smaller fee for each client. It comes out to
about $2k for the server (you need one and maybe 50-60Mb of disk for the
indices) and about $300 per client. There's no charge for the tape device
support, so you can support a mess 'o DATs if you have 'em. For exact
pricing look at your DECDirect catalog. Clients for MIPS and Sun and HP
and of course ULTRIX are available presently with more in the works.

	Let me digress for a moment on the topic of backups (not just to
add some technical stuff so people don't complain that I'm acting like
a salesrep) (incidentally, if you accuse me of acting like a sales rep,
I choose swords at dawn, have your seconds meet mine at USENIX and we'll
settle the matter like gentlebeings)

	*ahem* anyhow - I've noticed that tools like NSR or Networker
should cause users to shift their backup paradigms. A lot of folks have
come to me asking for a network backup solution that can handle a
"weekly backup of 20Gb" or something like that. The day in which it
was necessary to do full weeklies, I submit, it past. With the quick
seeking ability and small form factor of a DAT, it's perfectly reasonable
to do bimonthlies, in my opinion. As long as the indexes are kept,
you can recover a whole file system just about as fast as having it
on one reel used to be. Since the tape archive server knows what went
where, I've noticed that recovering stoff a year old out of my
tapes seldom requires mounting more than one tape, and has never
yet needed more than two.

	On my machines I have been doing nothing but incrementals
for over a year and a half. I haven't ever recycled a tape. I now
have 16 of them. I can recover quickly and precisely any rev of
any file in a matter of minutes.

	This strikes some people as utterly insane, since if I lose
a whole disk it'll take me longer to recover, but in fact I haven't
done that yet (lost a whole disk) and I'm pretty sure that if I did
I'd be able to probably retrieve the whole filesystem in an hour or
two. Not too terrible, really. Considering that with incremental
backups only, I have to change tapes about every month or so, the
administrative load is very light. This also means I don't even
NEED a changer. Typically if I need to recover something, the odds
are high that it's on the tape already in the drive.

	Has anyone else experimented with changing their outlook on
backups? My thinking went as follows:

	a) I used to like to have a monthly level 0 dump 'cuz I knew
		that if I wanted a file it'd be on that tape and I
		wouldn't have to grovel in bins for it
	b) if I lose a whole disk I will be able to recover in 2
		operations (1 - recover the level 0 and, 2 - add
		the latest level 5 and maybe 9)
	c) waitaminnit! if I have an index that lets me KNOW where
		my file is stored (and it'll just *tell* me "you dope,
		mount tape #3") item 'a' above is pointless
	d) if my full disk recovery plan in 'b' above requires 2
		steps, maybe 3, that's not a whole lot better than
		just shlunking a few DATs
	e) one royal PAIN with dump is that level 0 dumps don't know
		when a file has been *deleted* since the dump. if my
		tool's index lets me say "recover this directory as
		it looked on Jan 2, 1992" I am actually better off
		and less likely to have to shlunk DATs.

	Comments?

mjr.