3 Replies Latest reply: Aug 21, 2013 8:27 PM by Pondini
Jeffrey Jones2 Level 6 Level 6 (8,615 points)

I am contemplating renaming my hard drive — no particularly important reason, I just neglected to change it from “Macintosh HD” when the computer was new. But a question occurred to me: Will this cause Time Machine to start a complete new back up, making a new copy of everything?


MacBook Pro (15-inch Early 2011), OS X Mountain Lion (10.8.4), Firewire backup disk
  • Pondini Level 8 Level 8 (38,715 points)

    No, it should not.   OSX (and Time Machine) keep track of volumes (drives/partitions) via their UUIDs (Universally-Unique IDentifiers, assigned automatically when a volume is erased or formatted).  That's how you can have two volumes of the same name, even on the same physical drive, and OSX and TM won't get confused.

     

    The only caution is, don't rename while a TM backup is running -- TM will abort and restart.

  • Jeffrey Jones2 Level 6 Level 6 (8,615 points)

    Thanks. I finally got a chance to try it. You are right. It did not make a new copy.

     

    I was misled because I had experimented by trying it with a folder. I was using an old version of BackupLoupe (v 1.8.4), which told me that the renamed folder was copied.

     

    The first TM backup after the HD rename only took a few seconds, so clearly it was OK. Yet BackupLoupe implied that it did have a new copy.

     

    I have now updated to the latest BackupLoupe, which gets it right.

     

    (Oh look! Did I just push you up to exactly 38000 points?)

  • Pondini Level 8 Level 8 (38,715 points)

    Jeffrey Jones2 wrote:

    . . .

    I was misled because I had experimented by trying it with a folder. I was using an old version of BackupLoupe (v 1.8.4), which told me that the renamed folder was copied.

    Yes, files and folders that are renamed or moved really do get backed-up again.

     

    This only applies to volumes (disks or partitions).

     

    The first TM backup after the HD rename only took a few seconds, so clearly it was OK. Yet BackupLoupe implied that it did have a new copy.

    Not surprising.  It was comparing the names, not the UUIDs (that are kept in an Extended attribute on the folder in the backups that represents the backed-up volume).

     

    I have now updated to the latest BackupLoupe, which gets it right.

    Ah, good for them.    That's a very nice package, at a very reasonable price, and they do keep it up-to-date.  I'll get the update, too.

     

     

    (Oh look! Did I just push you up to exactly 38000 points?)

    Probably, but now 38010.  Thanks!