I am new to mlbackup/rsync and the concept of hard links, so I am a little confused after creating a backup data set via mlbackup.
So here's the scenario:
I am backing up "folder A" to "folder B". Inside "folder A", I have file "X", "Y", and "Z"; each file is 5mb therefore "folder A" is 15mb in size. I run mlbackup and the files are backed up to "folder B" for the first time. Now "folder A" and "folder B" are 15mb each.
Without any changes to "folder A", I run mlbackup again. A new "folder B" backup is created. It reads 15mb again (in Finder, Mac OSX 10.8).
Now I know the new "folder B" is just hard links to the original data, so I go to terminal and did a
du -sh folder B and it reads only a couple of kb. This is to be expected, right? So my first "folder B" is 15mb, and second "folder B" is a few kb.
Now my question is this -- in Finder, both "folder B" are 15mb each. So say if I wanted my "folder B" backups to be located in an external drive that only has 16mb of free space, what will happen? According to Finder, the total of the two "folder B" will be 30mb. But we all know in reality it is only 15mb (from first "folder B") plus a few more kbs (second "folder B")?
I know this is a pretty confusing question, but I really want to understand how it all works. Please let me know if there is anything I can clarify further.