Changing the LUKS Passphrase for Entire System
I have several encrypted partitions on my system and two of them are part of a RAID. There is just one passphrase to unlock the entire system. The system asks for that passphrase on boot. I wanted to change that passphrase so I went to the disk utility. The disk utility shows an option to "Change Passphrase" for each encrypted partition. So I wonder:
How is a single passphrase implemented even though there are several partitions?
How can I change that passphrase?
What happens if I change the passphrase of one partition but leave the others as they were?