Disc Permissions question

I have a partitioned external 1TB HD that I use for Time Machine back ups.

For some unknown reason the permissions changed to read only for me and Time Machine cannot delete any old data to make room for the newer back ups. This always worked in the past and I have not made any changes to the permissions. Not sure what has made this change.

When I attempt to change the permissions by right clicking the disc and selecting "Get Info" the option to change this is greyed out. Even after I unlock it with my password.

Any suggestions on how to change these permissions would be appreciated.

Info screen
-

Hi,
Only thing I can suggest is that you run 'Repair Disk Permissions' in Disk Utility on your Mac only...not your external drive because this doesn't work on a TM back up.

pendlewitch said:

Hi,
Only thing I can suggest is that you run 'Repair Disk Permissions' in Disk Utility on your Mac only...not your external drive because this doesn't work on a TM back up.

Click to expand...

Thanks, but no luck with that.

The permissions are wrong for that drive. Permissions for "system" are missing and should be read and write. Permission for you and everyone else can be "read only". Try adding "system" and give it read and write. Let's see what happens.

Added "System" as a user with admin permissions but it doesn't show up in the disk utility dialog box. Even after a reboot. Just the same as previous.

Any chance you unplugged the drive and plugged it into any other computer?
Or, that you've added and used a new user on your Mac?

I see there is a "locked" icon in the lower right corner of the Info dialog box. If you are an administrator, click on the lock and enter your password. Then you should be able to change permissions. After you finish be sure to lock the drive again.

Well now I am confused. I just got home from work and see that now the drive permissions have changed. All works as it should now. I never did anything. I have the only access to this computer.

I love this iMac but several strange things like this have happened recently.

Well now I am confused. I just got home from work and see that now the drive permissions have changed. All works as it should now. I never did anything. I have the only access to this computer.

Click to expand...

Gremlins? ;P

chscag said:

Gremlins? ;P

Click to expand...

I suppose...

The other two mysterious things that happened (I asked questions here about both) was my HD icon on my desktop suddenly changed it's name to my login password...never did figure out why. I renamed the HD and that solved having my PW displayed.

The second thing was a folder full of documents disappeared never to be found again.

Three unsolved and mysterious occurrences.

It probably is time to run some maintenance to sort the gremlins out but if you know roughly when the HD icon issue occurred go to Applications>Console>System Log Queries>All Messages and click the 'Earlier' tab at the bottom right until you reach the approximate time and see if anything unusual occurred around the time of a backup.

Sometimes this can be self-defeating though because it's difficult to understand...I call it 'Techlish'

I would power down and disconnect everything as well before a re-connection and reboot, including your external HD's power cord and it's USB or Firewire cable into the Mac.

Thanks for your input...will try all of the above.