I have a late 2014 MBP that I hook up to power and an external hard drive at work every weekday for 8 hours. I've been running Yosemite for less than a week, and before that I was running Mavericks.

Time Machine settings

Time Machine only seems to complete a backup once or twice every 2 weeks. Today I got a message that said, "No Backups for 10 days." I see similar messages all the time, and I think usually they say there haven't been any backups for 5 or more days. If I open Time Machine, I can see numerous entries in the timeline for the past several days--I assume these are the "snapshots."

What could be causing Time Machine to fail to complete for so many days in a row? Is there something I can do to improve its success? If not, am I at least safe as long as it completes once in a blue moon and shows recent snapshots in the Time Machine app?

Edit: after connecting at work today, the Time Machine settings dialog said something to the effect of, "Next backup: when disk is connected." I unplugged the disk, then plugged it back in at 1:57 PM and it changed to, "Next backup: Today, 1:47 PM." I still don't understand why it doesn't seem to detect the disk when I initially connect it.


1 Answer 1


Are there any console errors?

I would start with removing the plist, reboot, try again /Library/Preferences/com.apple.TimeMachine.plist

  • Within a few minutes after I plugged in the external drive this morning, the Console shows com.apple.backupd-helper: Not starting scheduled Time Machine backup: No destinations resolvable. I don't see any entry reporting that the external drive was mounted or even detected around that time. However, after unplugging the drive and plugging it back in this afternoon, I see messages for journal replay, mounted, /Volumes/external/.fseventsd out of sync, /Volumes/external/.fseventsd getting new uuid....
    – rob
    Feb 6, 2015 at 19:17
  • FWIW, I've also had occasional issues with my keyboard and other USB devices not being detected when I get to the office and plug in the powered USB hub that my keyboard, mic, hard drive, and phone are plugged into.
    – rob
    Feb 6, 2015 at 19:20
  • Have you tried to verify the disk in disk utility to see if its failing? And reset your PRAM. You may want to just completely wipe the drive and start a new time machine from scratch as fsevents is what keeps track of changes since the last backup. To speed things up you can exclude the external from Spotlight indexing There is a terminal command called 'tmutil' that you can run to get a more detailed explanation of whats going on at any instant. Maybe this post can point you in the right direction? apple.stackexchange.com/questions/90478/…
    – Hefewe1zen
    Feb 13, 2015 at 12:11
  • Second the point on the USB hub. I had one that always made a particular disk read-only but the disk was fine plugged in directly. (And either way, it had a separate power supply.). Also, the #$%^#$% backup disk I have now is "unplugged" when you can barely see the gap between the plastic part of the plug and the case.
    – WGroleau
    Mar 16, 2017 at 14:31

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