External disk problem.

[Erik P. Olsen]

I have an external 1 TB harddisk e-sata attached used for backups. The problem 
is that I have  few times lost connection to it. I have taken up the habit of 
suspending (to RAM) when I leave the machine for a while and the problem seems 
to happen when I reactivate the system though not every time. After a power 
cycle the disk attaches correctly again. There is no trace of the problem in the 
various logs so I am tempted to believe that it is caused by the suspend process 
rather than a disk failure but since it is my backup device I would like to be 
sure.

System: Fedora 16 with xfce 4.10
Kernel:  3.4.6-1.fc16.x86_64

Question: How can I run diagnose on the disk to see if it is about to fail 
permanently?

-- 
Erik.