will hfs work during standby? hibernation? thanks!
Depends.
S1 Standby (POS) - probably yes (you should test it)
S3 Standby (STR) - No (Computer turns off except RAM power)
Hibernation Mode - No (Computer caches RAM to disk and turns off)
MarkV
edit: POS = Power On Standby, STR = Suspend To RAM