HT204412: If a Time Machine backup takes longer than you expect

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Christian Simon

Q: Is 15 hours to backup 6 of 12G fresh install a "long time"?

I'm having trouble getting my TimeMachine backup to be recognized by Migrate. I've done three new backups over the past couple of days each time changing the partition map and format (read my related post here).

 

Then again, I'm wondering if I'm even making a complete backup each time. I turned "Computer Sleep" off (Energy Saver > Computer Sleep --> Never) and left screen sleep the same while connected to power. Then I started the latest backup. That was 0530h this AM when I left for work. Now it's 2030h and I'm seeing "Backing up 6G of 12G" in the TimeMachine file ribbon icon popup. 15 hours isn't enough to make a 12G TimeMachine backup?

MacBook Air, OS X El Capitan (10.11.4), null

Posted on Jun 17, 2016 5:44 PM

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Q: Is 15 hours to backup 6 of 12G fresh install a "long time"?

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  • by John Galt,

    John Galt John Galt Jun 17, 2016 7:30 PM in response to Christian Simon
    Level 8 (49,678 points)
    Mac OS X
    Jun 17, 2016 7:30 PM in response to Christian Simon

    The short answer to this question is "it depends" but yes, 15 hours is a long time. There can be various reasons for that, and various diagnostics you can perform to determine the reason.

     

    Unless I am not seeing replies in the other Discussion you referenced (which has been known to happen on this site) it seems you left some important questions unanswered. Please reply in that other Discussion. Those answers will bear upon this question.

  • by Christian Simon,

    Christian Simon Christian Simon Jun 18, 2016 4:02 AM in response to John Galt
    Level 1 (61 points)
    Apple Watch
    Jun 18, 2016 4:02 AM in response to John Galt

    I've updated the other post as you instructed. The truth of the matter is this is a new install and I'm conforming the install and TM in any ways recommended in order to secure this process. The only differences remaining are the partitioning schemes (and the system is smaller than the backup; this should be ok). Also, I've read this Apple post, "If a Time Machine backup takes longer than you expect", and used DiskUtility > Repair. This has had no noticeable effect other than the TM icon now reports, after running overnight: 14MB of 6G. Very slow.

  • by John Galt,

    John Galt John Galt Jun 18, 2016 6:59 AM in response to Christian Simon
    Level 8 (49,678 points)
    Mac OS X
    Jun 18, 2016 6:59 AM in response to Christian Simon

    It's a very good idea to test the ability to restore from a Time Machine backup. Otherwise, you might be using it for years without knowing whether your backup strategy is a viable one or not.

     

    I'll let the others respond to the questions in your other Discussion, but for the purposes of this one please refer to the following excerpt from If you can't back up or restore your Mac using Time Machine - Apple Support:

     

    System Requirements

     

    Before using Time Machine, you need a backup drive to copy your backed up files onto. Time Machine is designed to work with the following:

     

    • External drives directly connected to the USB, FireWire, or Thunderbolt ports on your Mac
    • The built-in drive of an AirPort Time Capsule
    • A USB drive connected to the USB port of a Time Capsule or AirPort Extreme 802.11AC base station
    • A networked volume served by OS X Server using Apple File Protocol (AFP)

     

    If your backup drive is connected differently, it might not work. Check with the device manufacturer for compatibility and connection information.

     

    Similar guidance is provided in Use Time Machine to back up or restore your Mac - Apple Support.

     

    Your other Discussion refers to using a locally mounted SD card for the backup device. Apple does not specifically indicate that is a supported configuration, so it might not work. It may appear to work, perhaps for a very long time, and you might even successfully restore from that volume, but you should be aware that a reliable backup strategy should use an unequivocally supported configuration. This site is full of tales of misery from those using unsupported Time Machine configurations only to find that they did not work in the dire circumstances in which they were required.

     

    I have never attempted to designate a SD card for the backup volume. If I did, it would strictly for experimental purposes not intended for actual use.

  • by Christian Simon,

    Christian Simon Christian Simon Jun 19, 2016 7:13 AM in response to John Galt
    Level 1 (61 points)
    Apple Watch
    Jun 19, 2016 7:13 AM in response to John Galt

    I'm finding the idea the SD card is unintended for this purpose, one of the few interfaces on the limited MacBook Air, to be very strange. I do see the passage you quoted does not specifically mention the SD slot, so I'm not sure what to say in response. Nevertheless, the SD does appear in the "Select a Backup Source" screen, and that's never been the problem with the procedure. It's always after recognizing the source--where's the TM file.

     

    I'm beginning to think the problem is a matter of complexity of my own previous configuration and settings distorting my sense of what I've had and done to solve the problem (i.e. my first TM wasn't a "complete backup", my second TM was't on the first partition, used VFAT, my third TM was not complete before I tested) and requirements of the setup (e.g. GUID, on first partition, formatted Apple Extended, and maybe some other things I don't know yet).

     

    I'm now on day three and I'm looking at "1G of 4G". Each time I use DiskUtility > Repair Disk utility the total resets.

  • by John Galt,

    John Galt John Galt Jun 19, 2016 7:57 PM in response to Christian Simon
    Level 8 (49,678 points)
    Mac OS X
    Jun 19, 2016 7:57 PM in response to Christian Simon

    Christian Simon wrote:

     

    I'm finding the idea the SD card is unintended for this purpose, one of the few interfaces on the limited MacBook Air, to be very strange. I do see the passage you quoted does not specifically mention the SD slot, so I'm not sure what to say in response.

     

    The Apple Support document clearly states "If your backup drive is connected differently, it might not work."

     

    What you are experiencing occurs to every other user that fails to follow instructions for using Time Machine... eventually. Consider yourself fortunate for having determined that outcome before you needed to restore from the backup. That's usually the point at which when people learn.

  • by Christian Simon,

    Christian Simon Christian Simon Jul 5, 2016 5:39 PM in response to Christian Simon
    Level 1 (61 points)
    Apple Watch
    Jul 5, 2016 5:39 PM in response to Christian Simon

    After several attempts my first backup on SDXC has completed, and it's recognized in the restore boot environment. Since I already heeded the recommendations for partition map and format, I'll not repeat these details here. I was stuck on one backup for a week. It was rediclious. Everytime I restarted or performed Disk Repair, the clock would reset, but then strangely expand both sides of the memory meter (done : total)!


    What finally worked was: Don't partition the SD card.

     

    After I restarted with a single partition, I was able to complete the backup. It's encrypted, too. But let's not get too excited, because it still took just under a week! That's a fresh install of OS X on a wiped drive. Nothing extra (except I did back up a few iPhone photos).

     

    I created a crontab job with the terminal command, $tmutil status and appended the output of this command to a log file. With this I was able to follow the progress and feel like it was still working. If I would have thought of it, I would have run this crontab from the beginning (without restart, cuz if you restart, the progress resets). It would be interesting to plot the progress of a basic TimeMachine backup to SDXC!