Our network has two Backup Servers (BU1 & BU2), each running Symantec Backup Exec 12.5, each with an Overland LTO4 Tape Drive attached. The two Backup Servers run each night at the same time - BU1 runs backups of our Exchange Servers, BU2 runs backups of our other LAN Servers.
The Job Rate for both Backup Servers has been around 1,300 MB/min for over a year. For no apparent reason, the Job Rate for BU1 last week suddenly dropped to 600 MB/min while the Job Rate for BU2 remained the same at 1,300 MB/min. I've yet to find any reason why the Backups from BU1 are suddenly taking twice as long as normal. The two Backup Servers are virtually identical and are on the same subnet, domain,etc.
Does anybody have any ideas of what to check and/or test to get the Job Rate for BU1 back to normal?
Both Backup Servers are Dell OptiPlex 755 Mini-Towers, each running Windows XP Professional SP3.