topic Re: Performance Drop after re-adding device in Operating System - HP-UX

Performance Drop after re-adding device

Rahim Johnson — Tue, 13 May 2008 12:06:22 GMT

We have an HP MSL6000 tape drive. I had to re-add the device to the dataprotector manager. After this was done the performance on the backups dropped and I have not been able to determine what changed.

For example the backups from one unix filesytem peformed as follows.
407.2 420.4 631.79 295.69 272.29 420.17 393.17 226.47 455.09

After the device was re-added the performance has dropped to these levels.
156.93 74.5 181.71 49.32 44.49 114.98 71.11 48.85 123.61

The filesytem is the same and the size of the data does not change much.

Interestingly, the performance on the backup of another unix server has not been affected at all.

Thanks

Re: Performance Drop after re-adding device

Steven E. Protter — Tue, 13 May 2008 13:27:58 GMT

Shalom,

Ideas bouncing around my head:

1) Bad hardware.
2) Device is not terminated properly or self termination is defective.
3) Lack of temporary space in /var on this system, due to core dumps or other problems.
4) SCSI ID on new tape drive not the same as the old.

ioscan -fnC tape

SEP

Re: Performance Drop after re-adding device

Rahim Johnson — Tue, 13 May 2008 13:33:03 GMT

Thanks for the reply.

We are using dataprotector manager on a windows server and we backup several Unix Servers. The backups still run fine but two have experienced this drop in performance. It could be a network issue but it started right after a re-added the backup device and autconfigured for all three servers.

So all three "clients" had to be configured.

I will check your suggestions. thanks