tuning NFS for large backups

All,

We do Oracle backups to NFS (they go subsequently to tape), and the load on both db side and NFS side spike significantly. The load spikes on DB are not _that_ large, however load spikes on NFS are very large (run queue in 20-50), especially during 'level 0' backups which are .5TB to 1TB in size. Unfortunately the disk array in this particular case seems to 'suck' badly (EMC Dell AX100) as it barely does over 20megs per second, but the network in between is at gigabit speed. But wanted to see what, from your experience, can be done to improve the situation, as we see similar issues across our other setups.

The db's are 9i/10g running on Linux. The NFS servers are also Linux. This particular NFS is 3.5TB, 4k block size. The Unix Admins have 'played' with some NFS tips, but with little success (or maybe with not enough effort). I am suspecting it has something to do with too much data being queued up on NFS side in memory and not being able to keep up with writes.

Any help, as always, greately appreciated. .......
We run Oracle 9iR2,10gR1/2 on RH4/RH3
remove NSPAM to email Received on Wed Nov 29 2006 - 03:19:33 CST