What is your bpduplicate parameters?

Is source and destination media server the same server (eliminating network)?

Are you duplication MPX source images to non-MPX copies?
If so, slow duplicates are to be expected.

Have you checked/verified BUFFER settings?
http://www.symantec.com/docs/TECH17706 

Do you have bptm log on media server(s) to track read and write process?

First confirm what Mary says, be sure you are not sending data across the network between media servers, the MPX is and issue but not a big deal, the next step is your buffers, the size of buffers you use to read and write are different you have SIZE_DATA_BUFFERS (read) and SIZE_DATA_BUFFERS_RESTORE (write) this is nice trick in case you source beffurs are smaller than 256kb, the other turn side is that you have a bigger buffer than 256kb, which tape drives cannot handle.

To isolate the issue run a DD test from your media server to the destination drives and check the speeds this will tell you if the issue is at OS, NBU or Source level, if the speeds are good than something is going on at NBU or Source level, the easy one here is to do the same with the source but in this case read from with dd command and send the data to null, this will remove the source from the equation or confirm the bottleneck, if speed is good than something is going on with netbackup configuration.

Hope this helps.

Regards.

Were the source backups multiplexed? If so, did you select the Preserve Multiplexing tickbox?
mpx -> non-mpx duplication will be S-L-O-W...

Please create bptm log on media server for troubleshooting.

Ensure that you have VERBOSE entry in vm.conf on media server to troubleshoot possible device errors. (NBU must be restarted for entry to take effect.) Device errors will then be logged in Event Viewer System and/or Application log.

If you have SIZE_DATA_BUFFERS_DISK defined, check for typo errors. Let say the intended value is 262144 but you my mistake wrote 214114. The result is painfully duplication speed (been there done that).

Hi@ll,

I have created the file SIZE_DATA_BUFFERS_RESTORE  with the same entry as SIZE_DATA_BUFFERS  and selected Preserve Multiplexing.

Now my duplicate runs fine.

Thank you all

Dirk