NDMP backups fail to filer attached shared drives after upgrade to NVBU 8.51 (4046520)

Date: JUN 2010
Product & Version: netvault 8.51
OS Version: all
Module & Version: NDMP 7.1.13,7.1.11, 7.1.5

Symptoms:
after upgrade to NVBU 8.51 NDMP backups report "Drive unavailable"

Were the installation has shared drives between two filers we see one NDMP attached drives go offline


Unable to share NDMP attached tape drives on NAS filers and problems browsing NDMP clients from backup window

If the customer browses one filer he can backup to the drives assigned/attached to it
but then tries to backup the 2nd filer to the same physical drives through that 2nd filers shared connection the backups fail.

If a browses using the ndmp plugin is executed on the 2nd filer were the backup was failing the problem reverses ,
backups are sucessful from the 2nd filer to the shared drives and the backups to drives from 1st filer that was working now fail.

When trying to attach shared tape drives between two filers we are only able to see the drive through 1 filer or the other filer but not both.



When browsing a NDMP client from backup window the close the browse, then in the same backup window try to brows a second filer we are unable to. But if we then close the backup window, open a new backup window, we can now browse the second filer but then we have the same problem browsing the first filer in this backup window.

Note: if we split the drives between filers i.e. one on each it is possible to attach and use the drives but even doing this requires q workaround. Which involves adding the library and one drive to first filer and saving the config, browsing the second filer, modifying the library then adding the second drive to the second filer


The following extract below from the filer messages file appears on the filer we unsuccessfully browse:

Fri May 28 07:04:36 CEST [tsg-vfs01: pac.peer.getName:info]: ndmpd: getpeernam