backup rate

[dadie]

Hallo,

First backup:
I have problem with rate of the backup. We use gigabit ethernet for backup. We backup from XP disk array to HP Sure Store where are 4 tape drives - dlt7000. Two of the drives backups 7-10 MB/s. Third drive backup only 1 MB/s. Why?

Second question:
Is it possible to increase rate on behalf of these condition? I upset that we have gigabit ethernet but we cannot use all possibilities.
Thanks Dadie.

 

[605]

I expect the save sets to be the problem - especially if you backup filesystems
with a lot of very small files, the data rate will drop extremely.

A good tool to test max performance is the "bigasm" test.
Please read any "Performance Tuning Guide" for details, for example from tis URL:

http://web1.legato.com/infodev/publications/NetWorker/perftun/7.0/perftune_7.0.pdf

 

[fazil1]

Hello,
I dont nessarily think this is a problem, Performance of a backup is not entirely dependant on GB ethernet, for exaple, you need to have a server with good data output, in other words if your notes server is so busy with notes process it wont have good data transfer during backup, your processor\memory and how many save sets you have specified per cleints also effect performance besides the paralism on the backup server and device speeds.
I would suggest disabling one of the drives to keep data flowing at heigher rate to the remaining drives, this way the shoe shining effects of DLT would not be so bad, either way the data tranfer rate to the other drives that you are getting is not bad atall for DLT.
Last thing is increse the DLT device's ability to handle multiple sessions, i.e increase it form 4 to 8.
Thanks
Bombay4U@hotmail.com

 

[eskolnik]

Is your problem with 1 MB/s always the same drive?
If not now many session are being sent to the slow drive?
Is it always the same client or the same subnet?


ed

Ed Skolnik