Knowledge base

Mac OS X 10.5.3 or later: Time Machine - Backup volume could not be mounted after changing network volume's password

Posted in Apple Mac OS

Products Affected

Mac OS X 10.5.3, Time Machine, Time Capsule

Symptoms

If you use Time Machine with a network backup volume (such as a Time Capsule disk or an AFP share from another computer) in Mac OS X 10.5.3 or later, "Backup volume could not be mounted" may appear in Time Machine preferences and back up attempts may not work.

This may happen if the password for the network backup volume has changed since Time Machine was originally configured.

Resolution

Log in with the user account that was used for the initial Time Machine configuration, then reconfigure Time Machine in System Preferences by selecting the backup volume again.

Alternatively, you can use Keychain Access while logged in with the affected user account:

  1. Open Keychain Access (in /Applications/Utilities).
  2. If the Keychains list is not shown in the upper-left corner of the window choose Show Keychains from the View menu or press Command-K.
  3. Select the "System" keychain in the keychains list.
  4. Find the Keychain entry in the System Keychain whose name matches the computer or Time Capsule you are backing up to and whose Kind is "Network Password".