Amarian

Q: What is the fastest way to update (duplicate) offsite Time Machine backups?

I have an external hard drive constantly plugged into my iMac which serves as a target for the hourly Time Machine backups, and to prevent catastrophic data loss in case of something like a tornado or house fire, I keep a second external hard drive offsite and bring it home once a week in order to copy my Time Machine backups over to it.

 

Currently I use the steps for copying a Time Machine database to a new drive as described by Apple; however, their instructions are geared toward migrating to a new/larger backup drive as a one time (or at least, not very frequent) event, and aren't ideal for routine updating of a second drive that already contains an older version of the backup file. 

After initiating the copy procedure by dragging and dropping the backup from one drive to the other, Finder takes 2-4 hours to index the millions of sparse bundles it contains, then I have to be around to "authenticate" the copy command, wait a few more minutes until I can accept the prompt to replace the existing file, and finally Finder actually begins copying the backup file, which takes 8-16 hours to complete (for less than 400GB over USB 3).


Besides the wear on my computer and drives from having to run from 10-20 hours straight every week for this backup alone, it seems a bit ridiculous having to copy the entire backup every week when probably greater than 97% of the files already exist on the target drive.  I've been looking around online for a while and found some articles about manipulating a previous version of Carbon Copy Cloner to handle Time Machine backup files, but I have the current version which no longer does this.


Is there a better/faster way to update offsite drives with Time Machine backups (that already contain most of the backup file), or am I destined to the irritating process described above if I want to keep an incremental backup offsite? 

(I use CCC to also keep a bootable backup offsite, but CCC's backups aren't incremental.)

iMac with Retina 5K display, OS X Yosemite (10.10.5)

Posted on Jan 6, 2016 12:14 AM

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Q: What is the fastest way to update (duplicate) offsite Time Machine backups?

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  • by Kappy,

    Kappy Kappy Jan 6, 2016 12:51 AM in response to Amarian
    Level 10 (271,174 points)
    Desktops
    Jan 6, 2016 12:51 AM in response to Amarian

    To duplicate a Time Machine backup should be done by cloning with Disk Utility.

     

    Clone Yosemite, Mavericks, Lion/Mountain Lion using Restore Option of Disk Utility

     

    Boot to the Recovery HD:

     

    Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

     

         1. Select Disk Utility from the main menu then press the Continue

             button.

         2. Select the destination volume from the left side list.

         3. Click on the Restore tab in the DU main window.

         4. Select the destination volume from the left side list and drag it

             to the Destination entry field.

         5. Select the source volume from the left side list and drag it to

             the Source entry field.

         6. Double-check you got it right, then click on the Restore button.

     

    Destination means the external backup drive. Source means the internal startup drive.

  • by LaPastenague,

    LaPastenague LaPastenague Jan 6, 2016 1:27 AM in response to Amarian
    Level 9 (52,596 points)
    Wireless
    Jan 6, 2016 1:27 AM in response to Amarian
    CCC's backups aren't incremental

    Actually that is not the case.. CCC does incremental backups.. but it doesn't preserve the history in the way TM does. Your snapshot of the drive will be exactly what it is now.. but the latest versions of CCC have added some new abilities.. worth a look.

     

    Also have a look at Chronosync .. not one I have used but lots of good reports.

     

    Unfortunately TM is just plain inefficient. Because of the delay between backups it must do a deep scan of the backup every time.. and this is just going to take a long time..

     

    IMHO CCC is the right way to do it.. since it is based around rsync it should be able to backup to your drive very quickly.. Worth giving it a go at least.

  • by Amarian,

    Amarian Amarian Jan 6, 2016 2:46 AM in response to LaPastenague
    Level 1 (0 points)
    Jan 6, 2016 2:46 AM in response to LaPastenague

    Actually that is not the case.. CCC does incremental backups.. but it doesn't preserve the history in the way TM does.

    Yeah okay...  Slight misuse of terminology on my part.  CCC does sort of preserve history with the "Safety Net" feature, at least with respect to protection against loss of accidentally deleted files (I don't know how it manages changed files), but it is really primitive compared with Time Machine.

     

    I have been using CCC for a few years now to maintain bootable backups, and it works great for that – like you said the backups are fast: daily updating for hardware redundancy takes <5min and weekly updating my offsite drive is usually less than 15min.  Although excessively paranoid by most standards, but I also want the file history and "timeline snapshots" which is why I'm using Time Machine at the same time.

     

    Also have a look at Chronosync .. not one I have used but lots of good reports.

    By virtue of quickly looking up ChronoSync I stumbled across Data Backup 3 For Mac, and I'll need to study them more carefully to be sure, but at least one of them might be able to replace Time Machine as my file history backup.  (The million dollar question, of course, is whether duplicating their backup files is any faster than Time Machine, but it's worth a shot.)  I don't know how I was able to spend dozens of hours searching for what I want to do without stumbling across either of these programs previously...

  • by LaPastenague,

    LaPastenague LaPastenague Jan 6, 2016 12:25 PM in response to Amarian
    Level 9 (52,596 points)
    Wireless
    Jan 6, 2016 12:25 PM in response to Amarian

    It is worth looking.

     

    Going back and looking at your first post.

     

    After initiating the copy procedure by dragging and dropping the backup from one drive to the other, Finder takes 2-4 hours to index the millions of sparse bundles it contains, then I have to be around to "authenticate" the copy command, wait a few more minutes until I can accept the prompt to replace the existing file, and finally Finder actually begins copying the backup file, which takes 8-16 hours to complete (for less than 400GB over USB 3).

    Have you tried using CCC to backup the TM disk to your other TM disk.

     

    CCC due to its rsync mechanicals underneath the nice gui exterior will actually handle that copy pretty well.. I suspect a lot faster than your present method.

     

    The only problem with this method is like any copy of a copy .. if there is an error or something wrong with the main backup.. that error is simply replicated to the copy.. that is why we tell people not to do copies of their backups.. rather to use TM ability to backup to two different destinations and swap the disks around.. only it does take a long while when you introduce the disk that has been away for week.. it is just that you then have two independent backups which is safer than backup copies.

     

    And you can do a straight rsync copy from the terminal. The huge advantage is the efficiency of rsync at copy only files that have changed.. and since TM files will mostly not change it should be able to handle the copy very fast.

     

    Tell us how data backup 3 goes..  data rescue, which is the top recovery software for dead disks, it should  be pretty good.