>
> So here's the deal. I have 3 database servers and 8 fileservers (3 of
> which are the database servers).
>
> I've devided the volumes into 7 approximately even sized groupings for
> dumps. I then do something like:
>
> Sunday: level 0 of set 1
> Monday: level 1 of set 1
> Tuesday: level 1 of set 1
> Wednesday: level 1 of set 1
> Thursday: level 2 of set 1
> Friday: level 2 of set 1
> Saturday: level 2 of set 1
>
>
> I do the same thing for all seven sets, except shifted by 1 (set 2 starts
> the cycle on Monday).
>
> The question is, what machines should be the beefy ones? Should I upgrade
> the 3 database servers, or will the fileservers be the ones getting pegged?
> Or, on the other hand, will the machine running the vos dump and sending it
> out to a tape drive need the most power?
Well, I can tell you how we're set up...
We currently have on the order of 40 fileservers, plus 3 dedicated dbservers.
The database servers and most of the fileservers are all sparc-1 class
machines, though we've been slowly upgrading the fileservers (we'd go faster,
but there are software considerations involved as well). When we're done,
we'll have some smaller number of Sparc 4/5 class fileservers, and the
same 3 Sparc 1+'s as dbservers; we've never seen a preformance problem
because of this.
We have about 500GB of data online; most but not all of that gets backed
up; unfortunately, I don't have exact numbers at the moment. Backups
are handled by a DECstation 5000 (that's a MIPS-based box, not an alpha),
with a single 8mm drive for backups and a separate drive for restores
and as a spare. We do fairly aggressive backups; each volume gets a
full dump every 6 months, and incrementals every month, week, and day.
We're just now approaching the limit of what that single system can
do in a day; with any luck, the next batch of improvements to our backup
system will both improve the performance of the existing system, and make
it possible to add additional drives and/or machines. Right now, the
performance bottleneck is not the machine; it's the tape drive and, in
some cases, the design of the backup system we use.
So, I'd reccommend improving your fileservers first. Of course, in your
setup (as in many others), the dbservers are also fileservers, so that
means they'll be upgraded too. With a small cell, that's probably OK;
in a larger cell, dedicated database servers can both improve performance
and make things easier to manage (e.g. you're never taking down a DBserver
to add or replace a disk). Of course, YMMV.
-- Jeffrey T. Hutzelman (N3NHS) <[EMAIL PROTECTED]>
Systems Programmer, CMU SCS Research Facility
Please send requests and problem reports to [EMAIL PROTECTED]
