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The icon for Macintosh HD (my boot disk) shows as a Time Machine disk. There is a file in the root of the disk. If I delete the file and restart the computer, the icon goes back to a normal HD icon. However, the file is recreated at some point on boot because when I log in again, the file has been recreated. If then reboot again, the icon goes back to being a Time Machine one.

Any ideas about what is creating this file and why? More importantly - how can I get it to stop? It looks like something thinks the boot disk should be a Time Machine volume, but what? shows the following messages at approximately hourly intervals:

19/01/2010 19:23:54 /System/Library/CoreServices/backupd[7459] Starting standard backup 
19/01/2010 19:23:54 /System/Library/CoreServices/backupd[7459] Cookie file is not readable or does not exist at path: /.<12 hex digits of MAC address for en0> 
19/01/2010 19:23:54 /System/Library/CoreServices/backupd[7459] Volume at path / does not appear to be the correct backup volume for this computer.  (Cookies do not match) 
19/01/2010 19:23:59 /System/Library/CoreServices/backupd[7459] Backup failed with error: 18 

Other possibly relevant information:

  1. The boot HD isn't the original - the original failed so this is a SuperDuper'd clone of the original drive.
  2. I used to use the same disk for a SuperDuper clone as for Time Machine.
  3. These are the same same symptoms as this and this.
share|improve this question is supposed to be at the root of your boot drive

This piece of advice from one of the discussions you linked to seems to be spot on:

  1. Open "System Preferences"
  2. click "Time Machine"
  3. click "Change Disk"
  4. click on "None"
  5. click "Stop Backing Up"
  6. restart your computer
  7. go back and set up TM to use your external drive

I can't imagine that the above wouldn't solve this, but if not you can also try deleting either /private/var/db/.TimeMachine.Cookie or /Library/Preferences/

On my machine neither of those files contain any data that specifies the drive, but you can open them with cat or nano and see if there is anything in them that points Time Machine to your boot drive.

share|improve this answer
I just had this problem and was coming here to superuser to see if anyone could answer how to solve this issue...I'm trying the shutdown-TM-reboot-reenable thing now to see if it works... – Bart Silverstrim Apr 27 '10 at 22:50

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