NetVault Performance issue after large memory upgrade (81763)

Date: May 2011
Product & Version: NetVault 8.5.3
OS Version: RHEL 4.6
Module & Version:
Application version: 32Bit

Symptoms:
After upgrading from 12 to 64GB of ram with a upgrade to a Large Memory Kernel for a 32Bit OS the drive performance has significantly slowed down to about 16-18Mb/s.

Drive performance statistics and the output plugin point towards a bottleneck with the device, in this case the standalone SCSI connected tape drive.

During a test the service on the Netvault server was stopped and and the Linux Binary DD was used next to
the HP Tape tools and these get a simialr data throughput.

Researches on the web point towards known performance degradations in such cases, which the tests and stats have confirmed.
The hardware vendor will need to be contacted for this issue.