4 Replies Latest reply: Jan 10, 2010 12:40 PM by enahs
enahs Level 1 Level 1 (0 points)
My chief interest in Time Machine is to backup the User file, especially the iPhoto library. I've also backed up the applications. Presently, I am using my Lacie 160 GB hard drive, and the backup uses only about 113 GB. The only substantial additions as time goes on will be photos. Time Machine says it will delete the earliest backups when the disk is full. But i am confused as to what that actually means. I presume it is checking the User file daily and then backing up only what is new. Sooooo, the original backup of photos would only be updated every day — and the original backup would still be available (with intervening additions) in the most recent backup . Is that correct? I guess what I am asking is whether I have anything to worry about as the disk gets full and a deletion takes place.

iMac Intel Core Duo, Mac OS X (10.4.11), IMac Graphite, G4 Titanium (10.3.9)
  • Pondini Level 8 Level 8 (38,720 points)
    enahs wrote:
    My chief interest in Time Machine is to backup the User file, especially the iPhoto library. I've also backed up the applications.


    If you have room, please consider letting Time Machine back up your entire system. That's what it was designed for, and protects you best that way.

    I guess what I am asking is whether I have anything to worry about as the disk gets full and a deletion takes place.


    In a word, no.

    Time Machine backups are very different from traditional backups. After the first full backup, yes, it only backs-up what's new or changed since the last one. But it makes "hard links" (sort of like aliases) to the backups of the things that didn't change. That means that every backup is, in effect, a full backup, and is how TM can show you a "snapshot" of your entire system the way it was at the time of any backup.

    When it deletes a backup, it deletes that set of "hard links." The only time an actual backup copy is deleted is when there are no more links to it (meaning, it was not on your system at the time of any remaining backup).

    So TM will always have backups of the current contents of your Mac, plus previous versions of things you've changed or deleted for as long as there's room.

    You might want to review these:

    Time Machine Tutorial
    Time Machine 101
    How to back up and restore your files
    Time Machine Features
    Apple - Support - Mac OSX v10.5 Leopard Time Machine

    and perhaps browse the Time Machine - Frequently Asked Questions *User Tip* at the top of this forum.
  • enahs Level 1 Level 1 (0 points)
    Pondini — many thanks. My intention is to get a much larger hard drive. But I just upgraded to Leopard/Snow from Tiger and used the Lacie that I had — and there's not enough space for a complete backup. So, for the meantime, I've backedup the critical stuff. BTW, Mac 101 is very useful. For the many years I've owned nothing but Macs, I didn't know about it.
  • enahs Level 1 Level 1 (0 points)
    And your piece in the FAQ section is outstanding.
  • Pondini Level 8 Level 8 (38,720 points)
    You're quite welcome.

    Thanks for the kind words, and the star!