🚀 go-pugleaf

A number of months ago we acquired a new Sparc 20 running Solaris 2.4,
to take over as our main file-server. At the same time, we purchased
a 5G 4mm DAT unit to handle over local backups.

Unfortunately, whilst dumps of filesystems local to the Sparc20 run fine,
as do remote dumps of Ultrix and OSF/1 boxes, remotes dumps of our Solbourne
S4000 machine (Sparc 2 clone, running Solbourne OS 4.1B == SunOS 4.1.2) take
forever. And remote dumps of the Solbourne that are started from crontab
take ten times as long!

Local ufsdumps are fine:           600-800K/sec
Dumps of our DECstation are fine:  400M in 20-odd minutes
But dumps of the Solbourne:        760M in *over* *four* *hours* !!

And that's *only* if I run the dump from an interactive shell.
If I fire of the dump from cron, such dumps would take (I project)
at least *two* *days* !! 

Previously, before moving backup responsibilities to the new Sparc,
dumps of the Solbourne would take an hour or two overnight. They now
take 6 1/2 hours, and then only if I run the dump script manually from
an interactive shell before leaving in the evening!

A typical command for our remote dumps (fired off by a complex shell script):
rsh remotemachine.dgs.monash.edu.au /etc/dump 0uf - /dev/rz0d | dd ibs=8k obs=8k of=/dev/rmt/0n

Can anyone provide any suggestions as to what the problem is and how to
combat it?

[Side question: can anyone suggest a more appropriate block size to use for
the DAT unit? 8K is way too small, I'm sure ...]

Michael Fuller
_______________________________________________________________________________
Systems Administrator,                                   msf@dgs.monash.edu.au
Department of Digital Systems, Monash University,        Ph:  +61 3 9905 3218
Clayton 3168, Victoria, Australia.                       Fax: +61 3 9905 3574