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HT1427: Mac Basics: Time Machine backs up your Mac

Learn about Mac Basics: Time Machine backs up your Mac

HT1427 How to create a new full backup using Time Machine

3223 Views 5 Replies Latest reply: Jan 22, 2012 7:25 PM by Pondini RSS
RobertDeveloper Calculating status...
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Jan 22, 2012 3:29 PM

If I understand it correctly Time Machine creates full backup at first and then incremental backups. Is it possible to create a new full backup and remove old backup including old incremental backups? I don't think I need for example to revert back to OS X Snow Leopard. I would like my current machine status to become starting point of a new clean Time Machine backup. What is the easiest way to do it? Should I switch off time machine, format my external hard drive and then tunr time machine on? Is there a better way? Is there an option "Create New Backup" (sort of create new hard disk image)?


MacBook Air (13-inch Late 2010), Mac OS X (10.7.2)
  • Pondini Level 8 Level 8 (38,710 points)

    Why do you want to do that?


    Once the drive gets full, Time Machine will automatically delete the oldest backups to make room for new ones. 


    Since each backup is, in effect, a full backup, there's no reason to make a new one. 


    The old version of OSX and default Apple apps won't take up much space on your backups, since there's only one copy there (unless they were updated, and then only the updates were backed-up again).    That's perhaps 20 GB for most of us.

  • Pondini Level 8 Level 8 (38,710 points)

    RobertDeveloper wrote:

    . . .

    If I wanted to restore the latest backup, time machine would have to go through the whole history.

    No, it doesn't.  It just uses the date-stamped backup folder you select (the same one it uses to display the backup in the "Star Wars" display.  It won't take any longer if there are lots of backups vs. only a few.


    You might want to review How Time Machine works its Magic for an explanation.


    I would like to keep it under 100GB

    The only way to do that is to limit the amount of space available, by making the partition smaller.  But why do that if you don't need to?


    In any case I don't see why I should keep 6 months long history of incremental backups.

    It won't hurt anything.  I occasionally go back farther than that looking for an old email I deleted, or file I changed several months ago.


    Using backup every hour would be overkill. Not because any backup performance issues, it is pretty fast and as a user I don't even notice that the backup is running on my Macbook Air, but I'm concerned how I would find older copy of a file in time machine if it was doing backup every 1 hour. I don't know if I could easily compare 2 files from different points in history.

    Usually there's no reason to do that.  If your HD fails, you restore the most recent one (unless you suspect damage, and want to pick an earlier one).


    To find each version of a file, you're supposed to be able to do that by selecting it in the "Star Wars" display, then use the arrow keys.  See Time Machine - Frequently Asked Question #15.  Some folks say that doesn't work for them, but it usually seems to.


    Or, use the 3rd-party Backup Loupe app.  See #A2 in Time Machine - Troubleshooting


    Is there a way to compare files and even entire directories? Let's say I need to compare all files on the entire har drive from yeaterday and a week ago (or a month). Is it even  possible?

    Time Machine won't, except to find differences with the arrow keys as above.  Backup Loupe (and Time Tracker) will only compare a selected backup to the previous one.


    If you're comfortable with UNIX and Terminal, the new tmutil command has a compare verb that might do part of what you want.


    Or does time machine only allow to roll back the whole drive.

    No.  You can restore selected items, via the "Star Wars" display as noted above.


    If I could compare files (for example source code) and see differences and then revert back only files I need, that would be perfect.

    That's tough because the "Star Wars" display takes up the whole screen; you can't put two windows side-by-side.  But you could go directly into the backups and do that via the Finder.


    If the app you use supports Versions, the Versions Browser can do that, sort of.  


    Is it possible to use Time Machine with /Developer/Applications/Utilities/

    You can't alter anything in the backups.  I don't know if that app will let you read from them or not.




    Message was edited by: Pondini  - typed calculatedrift when I meant compare (senior moment) 

  • Pondini Level 8 Level 8 (38,710 points)

    Next version of OSX. 


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