I have recently added a set of disks (file systems) to my back-up set
and that ended up with a failure due to "data timeout". I didn't even
know there was a dtimeout value to be specified in amanda.conf. I have
learnt that it is an idle time measured against the disks in question.

My question is now, how is this idle time measured and where is it
reported? 

Only by knowing what amanda sees of the idle time am I able to specify a
reasonable dtimeout value.

-- 
Regards,
Erik P. Olsen