Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I Recently bought a 2Tb external drive and configured time machine on my OS X 10.6.8 iMac. It started by making a full backup (approximately 1.6 Tb). Fine. I see a series of hourly incremental backups have run (a few hundred Mb each) A week goes by. All is good I have about 400Gb free on the backup disk. Suddenly it wants to make another 1.6 TB full backup. Disk full error. This implies that weekly (and I now assume, monthly) backups are not incremental. Is that correct?

share|improve this question

marked as duplicate by ChrisInEdmonton, Dave M, Tog, Moses, Raystafarian Apr 23 at 16:53

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

    
I read that article, but that's not the behavior I am observing. –  Mr. Bill Apr 1 at 17:53
    
No, that is not normal behavior. Something caused Time Machine to no longer recognize your current machine as the same for those backups. Probably going to need to wipe it and start over. –  Thebluefish Apr 1 at 18:03
    
Seriously? in service for 7 days and it needs a reformat? Some reliable backup. You know I went to Berkeley with Waz and have been a mac bigot for years, but I find myself increasingly disgusted with their products. –  Mr. Bill Apr 1 at 19:14
1  
@Mr.Bill I think (hope?) he meant wipe the backup from the time capsule and recreate a fresh backup, not wipe the machine. –  Ƭᴇcʜιᴇ007 Apr 1 at 20:12
    
I'm using an external 2Tb hard drive, not time capsual. I don't mind reformating the external drive, there isn't anything except the backups on it, but I am certainly not going to wipe my internal startup drive at this point. –  Mr. Bill Apr 1 at 20:21

1 Answer 1

Time Machine backups are all incremental once the first full backup has been made. But the system isn't at all smart about dealing with name changes. If you rename a directory, Time Machine will treat the change as if the old directory was deleted and a new directory was created with all the same files in it. Since it considers the directory to be new, fresh copies of everything under it will be made.

Changing the owner or permissions of a file will also trigger the creation of a fresh backup copy even if the file contents were not changed. Changing directory permissions does not trigger fresh backups of everything underneath, however.

share|improve this answer
    
Hmmm... All I've done this week is edit a few photos in Canon Photo Professional. I did change the name of one photo but no folder names. Even if photo professional was backed up in it's entirety along with all the picture files on my drive it still wouldn't equal the amount of space time Machine is asking for. –  Mr. Bill Apr 1 at 19:24

Not the answer you're looking for? Browse other questions tagged or ask your own question.