time capsule encryption
I want to encrypt my Time Machine data on my Time Capsule.
When I turn on the encrypt option, it wants me to delete the backups I already have then make it encrypted, or go back to unencrypted.
Is it possible to encrypt my backups going forward? yet keep the old backups?
If I activate filevault on my hard drive, will the time machine backups be encrypted too?
Is there a big performance hit with encryption?
I'm using osx 10.8.2 and the latest timecapsule firmware.
Thanks
Time Capsule 802.11n (4th Gen)