[bobhenr]

I was foolishly trying to alter permissions in the "Get Information" window for a partition on my external drive when I got an error message (which I did not write down). In any case, I lost all access to the partition. (I am the admin; there is one other user.)

(The partition has some business and personal data on it and I didn't want the 10 year old who used the computer to have access and I assumed I could change permissions in some way to block access. I did not change the permissions for myself. I don't remember what I was trying when the problem arose.) I have since decided it wasn't really all that important :-)

This is on a second generation 1.8 iMac running OS 10.4.3.

I could still see the disk in the Finder but could not open any folders or files. When I restarted, that partition was not visible anymore, though now it does show up in the Disk Utililty window. It has no system on it so OS X can't do anything to fix permissions.

I'm not a Terminal kind of guy but I did some research and found out how to A: run "diskutil list", which gave me the Unix name of the disk, and B: run "sudo diskutil repairPermissions disk1s11", (the "disk1s11" being the name returned by the first command for the partition with problems).

The response I got was:
Permissions are not enabled on the disk.
Error (-9973) "Permissions are not enabled on the disk" encountered attempting to verify/repair permissions disk1s11 12 | SIX

Is there any hope for this partition? If not, can I erase just that partition and reload the 19 CD's of backups I have for it without endangering the other partitions on the drive. I assume the answer to the erase question is "yes", but I also assumed I could safely play with permissions and that caused this problem in the first place.

[CharlesS]

Boot into Single-User Mode by starting up your Mac with the Command and S keys held down. Then, type these commands:

fsck -fy
mount -uw /
vsdbutil -a /
diskutil repairPermissions /
reboot

With any luck, that might get permissions re-enabled on your hard disk.

[Tomchu]

Fix Permissions only works on boot volumes, because OS X is aware of what permissions each system file should have.

Anyway, at the very least you should be able to mount the partition through Disk Utility. Once you do that, you can do "chmod -R 777 /Volumes/WhateverItIsCalled/*" in a terminal window.

[CharlesS]

Originally Posted by Tomchu

Fix Permissions only works on boot volumes, because OS X is aware of what permissions each system file should have.

Anyway, at the very least you should be able to mount the partition through Disk Utility. Once you do that, you can do "chmod -R 777 /Volumes/WhateverItIsCalled/*" in a terminal window.

That won't work, because it sounds like he actually disabled permissions somehow on the boot drive. The easiest way to fix that will be to boot into Single-User Mode and use vsdbutil, unless he's got some alternate boot disc that can boot to the Finder instead of just the OS X installer.

[bobhenr]

I don't have time to try any of the above because I have to go to work, but the last response seems to indicate the problem is more with my system rather than the problem disk. Am I reading that right?

I will first try the vsdbutil suggested by CharlesS, in any case.

But I've been thinking about doing a complete reinstall of my OS for reasons not related to this problem. If I did so, is it possible the disk would be recognized? i.e., are the permissions kept in the operating system rather than on the external disk partition? I'm asking this out of general interest.

This evening I can plug the disk into a neighbors mac to see if it works there. It will be easy to try, anyway. I'll update tonight. Thanks for the input.

[CharlesS]

Originally Posted by bobhenr

I don't have time to try any of the above because I have to go to work, but the last response seems to indicate the problem is more with my system rather than the problem disk. Am I reading that right?

I will first try the vsdbutil suggested by CharlesS, in any case.

But I've been thinking about doing a complete reinstall of my OS for reasons not related to this problem. If I did so, is it possible the disk would be recognized? i.e., are the permissions kept in the operating system rather than on the external disk partition? I'm asking this out of general interest.

This evening I can plug the disk into a neighbors mac to see if it works there. It will be easy to try, anyway. I'll update tonight. Thanks for the input.

No, the problem is that permissions are disabled on your boot disk. This is one of the few things that even reinstalling OS X won't fix, unless you reformat the disk. Fortunately, the vsdbutil command should hopefully fix that, and then repairing permissions should get the permissions of most system things back to what they should be, hopefully getting you back online without needing a reinstall.

[bobhenr]

CharlesS's suggestion didn't work. (Nor did, in case anyone is wondering, attaching the drive to a different computer). I assume the vsdbutil command works in many cases, but I think the files on the drive are toast anyway, so I'm just going to reformat and install from my backups.

I appreciate everyone's efforts to help. Luckily this situation was not a crisis so its not worth putting too much energy into. At least I've played with terminal a bit and done the single user thing and I've learned something.

[CharlesS]

Hey, before you reformat - does the Repair Permissions script still complain that permissions are disabled on the drive?

You could also try vsdbutil -i instead of vsdbutil -a / to initialize the vsdb database completely.

I hate when people give up this easily!

[bobhenr]

Thank You CharlesS

I hadn't done anything yet and saw your suggestion for vsdbutil -i and ran it. I now have my missing disk back, and all files appear intact. If one or two didn't make it, I do have the backups.

I promise not to give up easily the next time my Mac bites back.

[CharlesS]

Glad to hear that it worked.