Slow performance while restoring data with "Overwriting Exisiting FIles"

[Sean_-]

Hi,

When I have enabled "Overwriting Exisiting FIles" during data restore using NetBackup DataCenter 4.5, the restore performance (500KB/s) is very slow. Is it normal ?

However, I had far better restore performance (25MB/s), if the restoration is not overwriting any file, and restore to a empty space.

OS - Solaris 9
Server HW Platform - Sun Fire V880
Tape Library - Quantum M1500
Connection - Fibre Optic Cable (SC-LC) direct attach to server
NetBackup Version - NetBackup DC v4.5

Many Thanks !!!

Regards,
Sean

[Stumpr2]

Wow thats quite a difference 500K to 25000K. I didn't think that it would be that that much of a difference. I can appreciate the extra overhead that the CPU and I/O would require for an overwrite. Examples are extra checks for each file, links, inode comparisons, fragmented files, etc..But still, thats a huge difference. Are you comparing the same data for the metrics?

[Sean_-]

Yeah it is much difference ... I am not sure whether comparing the same data or not.

I have changed the FC-HBA card from qlogic to emulex, now seems better ... the performance will be more consistent.

Thank you.