Ewan66

Q: Back up following Time Machine recovery

I recently wiped my hard drive, reinstalled El Capitan and then recovered from Time Machine.

 

Trying to back up again with TM now, it looks as though it thinks all files have changed and it

backing up 460GB at a rate which will take days.

 

When I recovered from TM in the firs placen I didn't reload the saved settings, and the machine host name changed.

I've read on this forum that Time Machine doesn't use host name but device id. I've now reverted the host name in any case.

 

Any idea why TM would be backing everything up again and/or how to stop it doing so?

Many thanks... Ewan

Posted on Sep 20, 2016 12:18 AM

Close

Q: Back up following Time Machine recovery

  • All replies
  • Helpful answers

  • by norm123,

    norm123 norm123 Sep 20, 2016 3:43 PM in response to Ewan66
    Community Specialists
    Sep 20, 2016 3:43 PM in response to Ewan66

    Hello Ewan66, 

    Thank you for using Apple Support Communities. It's my understanding Time Machine is backing up a large amount of content after a recent erase and restore from a previous Time Machine backup. I use Time Machine regularly. I'd can see how larger and longer backups can a bit concerning. I am happy to help

    Since you've recently erased your hard drive, Time Machine is likely behaving as if this were the first backup.

    The first time you back up your Mac with Time Machine, it might take a long time to complete. This is because Time Machine copies most or all of the data on your Mac to your first backup. You can keep using your Mac while Time Machine works in the background to back up your data. 

    After the first backup is complete, Time Machine works in the background to back up only files that have changed since your last backup. This means your next backup is usually faster.

    If you want to pause a backup and finish it later, select the option to Skip This Backup from the Time Machine menu. Time Machine automatically tries backing up again later. If you want to start a backup manually (like overnight) choose Back Up Now from the menu to start it. 

    If a Time Machine backup takes longer than you expect

    Here's some additional information about using Time Machine.
    Use Time Machine to back up or restore your Mac

    Have a fantastic day!

  • by Ewan66,

    Ewan66 Ewan66 Sep 20, 2016 10:47 PM in response to norm123
    Level 1 (4 points)
    Desktops
    Sep 20, 2016 10:47 PM in response to norm123

    Hi,

    That's exactly my worry - Time Machine shouldn't be behaving as if this is the first backup. It should know it isn't because it's just restored a backup! Consider a single file in ~/foo. TM would have restored this file in my recovery process and it might have a date from mid 2015, say. TM should not now overwrite that file (which it itself has just recovered) because it hasn't changed (from the version it's just recovered). If it does, showing a new (unchanged) version of ~/foo then that's an error - the file hasn't been changed.

     

    Anyone else faced this problem?

     

    Many thanks, Ewan

  • by Ewan66,

    Ewan66 Ewan66 Sep 22, 2016 3:44 AM in response to Ewan66
    Level 1 (4 points)
    Desktops
    Sep 22, 2016 3:44 AM in response to Ewan66

    Bounce.... Anyone out there?