sync before sleep

I ask because the Time Machine disk may potentially get disconnected during the sleep period.
Paul Förster wrote on :

Hi,

... can anybody tell me whether Mac OS (Leopard) does a sync before I send it to sleep? I ask because the Time Machine disk may potentially get disconnected during the sleep period. I know this is generally not a good idea but I want to know if I have to definitely unmount it first. I know that it probably complains about a disk being removed but not unmounted first after waking it up again but if it's sync'ed then this shouldn't be much of a problem.

Sending the Mac to sleep and waking it up with the disk mounted is not a problem. I've tried that and it doesn't complain and everything seems to be fine so far.

So what if the disk is removed during the sleep period?