How do you md5 an entire disk in OS X?

Solution 1:

If you are not trying to checksum disk the running system resides on (this won't ever be consistent) you may try

dd if=/dev/disk2 | md5 -

Solution 2:

You could mount both filesystems (read-only, if possible) and then recursively checksum each file.

EDIT:

example command:

cd /Volumes/xyz

find . -type f -exec md5 {} \; | cut -c15- > log1.txt

15 in this case is the string length of /Volumes/xyz or what ever your mount point is.

Do this on both file systems and make sure the filenames do not have the starting root path (by using cut). Then use the 'diff' command to compare the 2 files.