FileVault and Time Capsule on Mac
From Mavaball
This page contains notes about getting Mac's Time Machine software working with Time Capsule, especially when the FileVault home directory encryption is enabled.
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Overview
Mac OS X (versions 10.5 and higher) comes with the Time Machine software for automatically backing up your Mac's hard drive. Mac OS X also comes with a feature called FileVault that allows you to encrypt the contents of your home directory. Unfortunately, these two features don't work seamlessly together. You have to log-out with a backup disk connected (like a Time Capsule) for Time Capsule to backup your encrypted home directory.
10.5.6
As of OS X version 10.5.6, there is a problem where Time Machine no longer backs up an encrypted home directory during log out. It appears that (as of Jan 11, 2009), this problem is unresolved.
Links
These links describe the problem in more detail:
- Mac OS 10.5.6 and Time Machine - Blog with lots of comments describing workarounds.
- Topic : 10.5.6 Update Breaks Time Machine backup of FileVault home folders? - Discussion thread that seems to get close to the answer.
It appears that time machine is backing up the home directory as part of the regular backup, but it also appears that these backups are not getting encrypted. So, your data is probably safe, but may not be secure.
A fix for backup errors
Sometimes if you (accidentally) stop a backup in the middle, you get a temporary backup file (actually folder) that is corrupt and causes all subsequent backups to fail.
To file this problem, you have to manually connect to your backup disk (in this case, a Time Capsule), open the sparsebundle file, and look for the partial backup file and delete it.
Steps:
- Open up your Time Capsule shared folder (or other shared folder for backups) and mount the folder
- Look for the sparsebundle file that keeps all the backups. It will be named some like ComputerName_001ec20cea0b.sparsebundle
- Double-click on the sparsebundle file to mount it. You might see a dialog box that says "Opening ComputerName_001ec20cea0b.sparsebundle... Checking Volumes". For most backups, this check will take hours because it requires transferring many GB across the network. Just press "Skip".
- A new folder will be mounted in the Devices area of Finder, called "Backup of ComputerName" (where ComputerName is replaced by the name of your computer). For command-line users, this folder is mounted on "/Volumes/Backup of ComputerName"
- Click on this folder and go to the path "Backups.backupdb/ComputerName". It may take a while to open the ComputerName folder.
- Look for a file named something like "2009-01-31-162208.inProgress" (where 2009-01-31 is the date [Jan 31, 2009] and 162208 is the time [4:22:08pm]). For command-line users, this file will be at "/Volumes/Backup of ComputerName/2009-01-31-162208.inProgress".
- Delete this file (actually it's a folder, but only command-line users will discover this). Finder will ask you for your password. (Unfortunately I haven't figured out how to delete this using only the command-line, but it's some variant of "sudo rm -Rf 2009-01-31-162208.inProgress")
- Unmount all the folders so that Time Machine has access to them again.
- Tell Time Machine to "Backup Now" so that you can verify that it works again.
Viewing partial Backups
As a side note, you can view the files within these partial backups (for example, in cases where you lost your hard disk, but only have a partial back-up on the server). Just go to the same file as above (e.g., 2009-01-31-162208.inProgress) and right-click on the file in Finder and select "Show Package Contents" (this file is actually a folder). The first level directories are weird hexadecimal numbers with hyphens, but the sub-folders contain copies of real files on your system. The trick is that the file you're looking for could be in any of the top-level hexadecimal folders. You'll have to search for the particular file you want. (Nobody said it would be easy, but at least the data is accessible, somewhat.)
