Last weekend I reinstalled MacOS X Leopard on my MacBook Pro for it had some strange errors I couldn’t get rid of. Of course I did a Time Machine backups ahead to have my data safe during reinstallation. I didn’t chose to restore my personal account from a Time Machine backup during the installation as I wanted a clean and fresh system with all programs and settings setup up new and manually. This time I selected to create FileVault user account. This means my home folder is actually an encrypted image file. This image file will be descrypted and mounted as my home directory during login and gets automatically closed and encrypted when I log out.
This worked very well for the first hours. But then during manual installation of some programs and copying my backed up files a kernel panic occured with the grey screen of death. That’s the last thing you wanna see when you have a mounted encrypted image.
After reboot I still was able to login and everything looked OK. But my keychain was damaged. This wasn’t a big problem for the moment as there where only a few apps which made entries there. I repaired the broken keychain and everything was OK.
Then, after finishing my restore I tried to delete the old Time Machine backups from my external disks. This isn’t as easy as it seems. Just dragging it into the Trash bin and empty the Trash will take hours as the Backup consists of million of files. I tried that before….
This time I tried to delete the Backups.backupdb folder from the disk with simple Unix commands (rm -rf ). But this doesn’t work firsthand. Even as superuser I wasn’t able to delete the files. Always got a “no permission” error message. I then checked the usual suspects mds (Spotlight Metadata Service) and hidden file attributes (xattribs). But that didn’t helped.
Finally I connected the disk to another MacBook with the old Tiger 10.4 MacOS X and tried to erase the files over there. This worked well. So Tiger doesn’t care about special settings of these files and did it’s job.
After that I tried to start a fresh and clean backup with Time Machine again. But Time Machine told me that it couldn’t do a backup of a FileVault secured home folder while the user is logged in. This is logical but sad. As this is a laptop computer and I’m the only user I’m almost always logged in when this machine is on. And to extra log off to have a backup done is not really practical. So I decided to kick FileVault for a convinient Time Machine backup. This took a lot of space on my hard disk during the unencryption and about 2 hours.
But now everything is fresh and clean and even PictureSync is working properly again.