I'm having recent troubles with an SBS 2011 server (HP Proliant ML350) where the backup is causing the server to become unresponsive, and the only way we can fix it is by doing a hard reset (holding in the power button until it turns off, and then turning it back on - not really good for the server).
The problem has only started in the last week, after running fine for the previous 4-5 months. There are two USB backup drives being used (both Seagate GoFlex 1.5TB), and the problem happens with both drives. I have run chkdsk on both of these drives and they come up and clean (no errors). I have used the same model of drive for other SBS 2011 backups without problems.
The server itself has two drives (C: and E:) - have run chkdsk on these and again - all clean.
Just prior to the server freezing, there are lots (thousands) of Disk Errors (Event ID 7) in the System log, saying "The device, \Device\Harddisk2\DR4, has a bad block).
Any suggestions as to what I should do next to fix this? This one's a bit of a puzzle.