Has anyone tried doing any performance tuning with NDMP for NBU?

I was testing from a RAID0 (3 disk set) on internal 10K disk and couldn't
get above 119MB/sec (no tuning).  I ran test to /dev/null and only got up to
about 120GB/sec so my testing needed to move to something with faster disk
and I/O.

I decided to try to get better read speeds from the DMX we have on a Celerra
we have for testing via NDMP.  This should give me the 2Gb Fiber Channel
speeds along with the better performance disk and cache. Incidentally, most
of our data is on NAS so NDMP is the only real option.

My testing environment:

   - NBU 6.0 MP4
   - LTO-3 physical & virtual drives (just to test the differences in
   performance)
   - Cisco SAN - fabric 2Gb (not oversubscribed)
   - EMC NSX Celerra (5.5 code) with EMC DMX3-24 fiber channel 10K 146GB
   disks in a RAID5 config (yes, I realize that the RAID level is what might be
   killing my performance but I'm hoping the cache will at least off-set this).
   - Data: contrived files that are 50MB in size and compressible by 4.3:1
   written sequentially totaling more than 500GB in total data.

The environment is running the default NDMP settings on the Celerra. Anybody
have any recommendations for tuning the NDMP config on the Celerra [e.g.
buffer size, etc.] to get closer to the 150+ MB/sec rates that I should be
seeing?  Perhaps config changes elsewhere?

Brian J. Greenberg
-------------- next part --------------
An HTML attachment was scrubbed...
URL: 
http://mailman.eng.auburn.edu/pipermail/veritas-bu/attachments/20061214/8f8c4cfe/attachment.html