Hi Christoph,
> Some informations about the hardware we use: The backup server is a
> Athlon 1GHz PC with 256MB Ram and SCSI harddrives (holding disk is
> IDE), network is 100MBit switched. Most backup clients are Pentium
I wonder is IDE holding disk is the best solution, did you check i/o
statistics on your server machine? How much holding disk is working?
Also did you check your network? I had pluged Amanda server to a
switch, and when I was wondering why the network seemed so slow, I
found out that the server was undergoing more than 200 collisions per
second. I changed UTP cable and switch port, no collision, working
much better. How about increasing the netusage limit? Default 600kbps
is ridiculously low for switched fast Ethernet, especially if you run
amanda at night when the network is empty.
Beside, that is only one idea, to Amanda project team, what about
having Amanda using 2 holding disks, one for dumping, while the other
is writting to tape? Would limit the seeks on the disk.
> III with about 256MB Ram and SCSI harddrives. Our backup medium is a
> HP-DLT1 drive, which should be able to write about 6MB/s (if i can
> believe HPs technichal description). I copied the tapetype definition
You could run tapetype, it will only take one night or so and could
confirm the data.
I also discovered a tool called cstream (at least on FreeBSD) that
generates random data and sends them to the tape, it was nice to check
the minimum speed needed so that the tape would stream (about 6MB/s
for Tandbergs SLR 100). I found out for example that tar to tape could
never acheive the needed speed (empty machine, PIII 800, 40MBs
SCSI). Adding more i/o buffer would stream until the buffer is empty
and needs to fill up again.
> in the amanda.conf from a faq-entry on www.amanda.org. All machines
> use Amanda 2.4.2pl2 on SuSE Linux 7.1.
>
> A complete level 0 dump of all harddrives currently is about 45GB
> (25GB compressed) and needs about 16 hours to run. In the current
> disklist there are 14 machines with 39 harddrives/partitions to
> backup.
Did you check spindle parameter in the disklist file? I use SCSI
target as the spindle number for each partition.
About spindle number, I need an advice. I will back-up about 50
Windows machines, with Samba/Amanda. Should I have one number per PC,
or is that better that have some machines running in parallel?
Best regards,
Olivier
