this only works for the system partition.
if you do store your system on a single partition, you're fine.
if you have stored files on a second partition Squeeze won't work.
external drives neither...
the developers may to lift this restriction in later releases, support told me.
Squeeze 1.1 now allows folders in non-boot volumes to be compressed, as long as they are not located in removable media. Please, upgrade to the latest release
The reasons for still excluding removable media are:
- If you mount a volume in an OS other than Snow Leopard, compressed files cannot be read. We prefer to exclude those volumes rather than cause any inconvenience to users that might not be aware of this limitation. Note, however, that copying a file to any location or sharing it from your Snow Leopard computer will work correctly in all cases.
- Squeeze being configured to receive filesystem notifications from a folder in removable media would prevent the volume from being ejected while Squeeze is running. Again, this would potentially be the cause of frustration for some users.
We are looking at ways to further relax the non-boot volume restriction. However, Squeeze 1.1 allowing internal disks to be processed does help with a lot of configurations.