This is a refinement of a question I asked yesterday, the product of deeper research I have done since.
The script that starts CrashPlan has, as it should, a hard dependency on $local_fs in its LSB Required-Start entry. The problem is coming about when this dependency is satisfied without the USB volume being mounted. Therefore CrashPlan thinks it has to create its backup destination and the conflicts begin.
My understanding of $local_fs is that everything in mtab will be mounted before it is satisfied. Is that not the case? Are there options I can add to the mtab entry to change this behavior for the volume in question?