I have a MacBook Pro 15" with the SuperDrive removed. As the primary boot drive I have an SSD, and in the SuperDrive slot I have a larger spinning disk.
Each night, I use SuperDuper to clone the SSD to one (of three total) partitions of the spinning drive.
This gives huge advantages, in that even in the event of a total SSD failure, I only have a minute or two of downtime, as the backup is always with me, and bootable.
However, it also means that the MacBook also sees two copies of every installed app (this is really annoying). It also means I have a disk showing in the Finder that I'd just as soon have hidden (less annoying, but would ideally not show).
Enough intro... what I would like to do is have the Backup Drive NOT mount at startup. In fact, I would like for it to mount ONLY immediately before a SuperDuper backup, and then unmount as soon as the backup is finished. I want to keep the OTHER two partitions on the spinning drive mounted at all times.
Surely someone already has a script/solution to do this. Can't be that of an off-the-wall request, is it? Or am I missing a feature of either SuperDuper or Carbon Copy Cloner that does this already?
EDIT: I have discovered where SuperDuper does this... kinda. If you have a Scheduled Job (run backup at 2am) and you run it manually (with the "Copy Now" button) then it will mount an unmounted drive, do the backup and then unmount the drive. However, if you do it this way, SuperDuper will not quit automatically. This feature also does not seem to work when the job runs at it's scheduled time.