At some point after upgrading to Lion my Time Machine backups have stopped firing on the hourly interval. It works manually, but not automatically. It also works first thing in the morning when I plug the external drive into my laptop.

I have basically gutted the Time Machine config files, launchdaemon files with no luck. I've even reformatted my TM drive. So far, no matter what I do, TM just never fires on the hour.

The interface shows when the last backup occurred as well as when the next one is set to happen. When the time comes, TM never backs up but the "next backup" time is moved up one hour as expected. I have no errors in console.

Is anyone else seeing this and if so, did you get it fixed?

Update with logs from today, last backup is indicated as 9:01AM

10/11/11 7:09:55.020 AM com.apple.backupd: Starting standard backup
10/11/11 7:09:55.272 AM com.apple.backupd: Error -35 while resolving alias to backup target
10/11/11 7:10:05.287 AM com.apple.backupd: Backup failed with error: 19
10/11/11 8:18:07.490 AM com.apple.backupd: Starting standard backup
10/11/11 8:18:08.386 AM com.apple.backupd: Backing up to: /Volumes/Time Machine Backups/Backups.backupdb
10/11/11 8:18:34.350 AM com.apple.backupd: 48.19 GB required (including padding), 731.56 GB available
10/11/11 8:50:08.828 AM com.apple.backupd: Copied 15193 files (38.5 GB) from volume Macintosh HD.
10/11/11 8:50:20.136 AM com.apple.backupd: 20.83 GB required (including padding), 693.03 GB available
10/11/11 9:01:59.574 AM com.apple.backupd: Copied 3613 files (15.8 GB) from volume Macintosh HD.
10/11/11 9:02:12.462 AM com.apple.backupd: Starting post-backup thinning
10/11/11 9:02:12.462 AM com.apple.backupd: No post-back up thinning needed: no expired backups exist
10/11/11 9:02:12.848 AM com.apple.backupd: Backup completed successfully.
10/11/11 9:05:36.179 AM mds: (Error) Backup: Couldn't stat source path '/Volumes/MobileBackups/Backups.backupdb/workbookpro/2011-10-11-081810/Macintosh HD/Users/dustin/Library/Application Support/Firefox/Profiles/ytgtapq6.default/extensions/trash/[email protected]/install.rdf' -- importing from backup path instead

EDIT: Some more info, as this is STILL a problem for me. I have now found that com.apple.backupd-[auto|wake|attach] all quit at about the same time, either at the time the backup should fire or just before. The job then never runs. There are no logs at all that the services quit or why.

  • Can you open Console.app and see if there are any error messages? Sometimes the app doesn't warn you except for a tiny entry in a log file somewhere. If you do see an error message there, it will probably be so obvious you'll be upset that they didn't put it in the UI. :/
    – Art Taylor
    Commented Sep 22, 2011 at 5:24
  • If you unplug the external drive during the day and plug it back in, does it again work for one cycle, like in the morning? Does it work if a minute before the backup is about to launch you access a file on the drive so it spins up? Does it work if you plug the drive in another USB port (I had Backup.app consistently fail on one port and work fine on the other).
    – root
    Commented Oct 10, 2011 at 17:03
  • As Mr. Taylor says above, you'd probably want to look in the log, an old one-liner to enter in Terminal I used to use which may still work to dig out the last 30 lines of output(over the last 72 hours) is: syslog -F '$Time $Message' -k Sender /System/Library/CoreServices/backupd -k Time ge -72h | tail -n 30 If you REALLY want to get medieval on its butt, new in Lion is tmutil, which may give you a more tools to attack the problem with. Another thing to check is the partition format of the drive(GPT versus APM or MBR), as Lion supposedly got more restrictive with what it will back up to. Commented Oct 10, 2011 at 17:59
  • I've reformatted the drive, reset all of the TM preference files throughout the system and it still won't backup on the hour. It does the local snapshots just fine and the system preferences interface shows when the next backup is going to run, but when that time comes the backup isn't done and the time is just incremented to the next hour.
    – Dustin
    Commented Oct 10, 2011 at 18:06
  • Thanks for the log messages. If you don't filter for 'backupd' and find the message "Error -35 while resolving alias to backup target" can you post the messages just before and after it? Commented Oct 11, 2011 at 20:50

2 Answers 2


I know you've said there are no messages in Console.app, but you haven't specified how you've searched. So firstly follow the steps below, and just add a comment to say whether you find anything.

  • Open Console.app
  • Select 'All Messages' in the left hand pane
  • type 'backupd' in the search box in the top right

Are there any messages in here related to the backup doing anything at all?

  • See updated post
    – Dustin
    Commented Oct 11, 2011 at 19:06

Finally found the issue. Turns out in testing an app that I write, I accidentally created a com.apple.TimeMachine.plist under my root user that disabled automatic backups from occurring. I deleted the offending file and my backups are now working on the hour as expected.

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