I have a very large external Firewire drive with multiple partitions. Most of the time, i only want the Scratch partition mounted. But if I drag any one partition to the Trash to eject it, all partitions on the volume will unmount.
To prevent this, I could use certain applications to just unmount the unneeded partitions, use a utility to just mount that particular partition, or I can keep open a file on the Scratch partition when ejecting the others. So, I keep a simple AppleScript open at the top level of that partition. The script unmounts the partitions and quits. Because the script is open, the Scratch partition won't eject.
Mac OS X Hints
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