VTL Block size for Oracle/RMAN backup

Question

All,

Am currently investigating a performance issue on a client's site where they are using NetWorker 7.4 with Oracle Module to backup database to Sun VTL.

Currently the backup is delivering about 60~70MB/s to VTL but the customer claims the backup is faster to their LTO3 Physical tape library - not seen this as the backup times are so extended that run times can take ~48hours per database

Has anyone done any work to establish the best block size for this type of backup ? Additional information, Oracle 10 on tru64 and the server is a storage node with san attached VTL, the server has 2Gbit F/C HBAs.

Thanks in advance

IKP

IKP1 · Answer

All,Resolved the issue, set the devices to the largest supported by NetWorker and the backup throughput to the VTL more than doubled.IKP

ble1 · Answer

By using biggest bs for device you will also consume more tape space than you would usually. I'm sticking to 256KB for now tape_perf utility is broken in recent versions of NW so I could not test it on our new EDL, but apparently fix is on the way.

NetWorker

VTL Block size for Oracle/RMAN backup

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