Backing Up A Mac Running Tiger

July 9, 2005 8:32 PM

I'm on a G5 running Tiger, referring to a user account lacking admin privileges, with a backup strategy of dragging my User folder to an external hard drive once a week. Since upgrading to Tiger, though, I've been informed that "You may need to enter the name and password for an administrator on this computer to change the item named 'Library'." I've duplicated this on another computer. What's going on here? First, I'm only copying the Library, not changing it, and second, why do I need an administrator password? This is my User library, I thought that it and everything else within my User folder was by definition owned by me, and that even if I did want to modify something in the Library I wouldn't need a admin password.
posted by boombot to Computers & Internet (20 answers total)

Hmm. Simple things first. Try repairing permissions on the boot drive using the Disk Utility (Applications->Utilities->DU, select the drive on the left, and "repair permissions" button on the bottom). Also, select your user folder, click command-I (Get Info), and drop down the ownerships and permissions menu (near the bottom). Drop down the "details" menu as well within that. You should see your own permissions set to "Read and Write," and then click "apply to enclosed items" (it will ask if you are sure).

Also, you might want to set your backup drive to "ignore permissions on this volume: (same routine, but start from selecting your backup drive). This assumes it's not actively a volume on your machine most of the time, and that you only plug it in or turn it on to backup.

Yeah, permission management in OSX (via the GUI especially) is still a weak spot.

PS -- I am still running Panther (server) so there may be something specific to a Tiger upgrade here. Did you look in the Apple Knowledge Base?
posted by realcountrymusic at 9:24 PM on July 9, 2005

So what folder are you actually copying? /Users? /Users/boombot? /Users/boombot/Library? /Library?

Also, when you say you can duplicate this is it with the same external drive on the other machine? I wonder if the problem isn't the permissions on the external drive itself.
posted by sbutler at 9:26 PM on July 9, 2005

Best answer: Ahh... I bet I know what's up. Run this command from Terminal:

tulkas:~ sbutler$ find . ! -user sbutler
./.ethereal
./.ethereal/recent
./Library/Favorites/Documents

Ignoring the ethereal stuff for the moment, it looks like Tiger installed a symlink inside ~/Library/Favorites. "Documents" is owned by root and points to "../../Documents". Anyways, this is probably just an artifact of the post-installer. Typing "sudo chown boombat:boombat /Users/boombat/Library/Favorites/Documents" should fix things up.
posted by sbutler at 9:31 PM on July 9, 2005

So what folder are you actually copying? /Users? /Users/boombot? /Users/boombot/Library? /Library?

I think boombot said it was Users/boombot/Library, though not with the path. I second the likelihood that it's the external drive. Probably you set it to permit you to read and write under Panther, and have forgotten, or it just worked that way, but somehow that got mussed up on the Tiger install. Are you the only user, boombot? If so, do you not grant yourself admin privileges for security? Good practice, but it would drive me nuts not to be the admin on my personal machines, which are of course not shared or serving.
posted by realcountrymusic at 9:34 PM on July 9, 2005

sbutler, fascinating. I haven't got the patience to search the Apple Knowledge Base, but if this happens routinely on Tiger installs, it must be there.
posted by realcountrymusic at 9:38 PM on July 9, 2005

minor offtopic for realcountrymusic: is it even *possible* not to have an admin-enabled account?

Of course! You can disable all sorts of privileges in accounts. I run OSX server on most of my boxes and never configure other users on the others, so maybe there's a difference with client. But you have to be able to create lower-privileged user accounts.

These can be useful on personal machines as well, by the way, which is why I thought it possible that boombot was actually working in a non-admin account even if s/he is actually also the admin user. In theory, it's good practice for security, though more so on Windows than Mac.
posted by realcountrymusic at 10:33 PM on July 9, 2005

Response by poster: I have Repaired Permissions, and have duplicated the issue on another machine with another external HD.

SButler, when I ran "find . ! -user sbutler" three results were returned: two files in my Library, one in my Pictures folder. What did the command do, and what do the results mean?
posted by boombot at 10:41 PM on July 9, 2005

I have Repaired Permissions, and have duplicated the issue on another machine with another external HD.

How duplicated? With a different user folder similarly underprivileged, also tiger? Are both machines upgraded to Tiger or did you do clean installs and copy over user files?

Did you try ignoring permissions on the backup drive?
posted by realcountrymusic at 10:44 PM on July 9, 2005

Well, the "." means to start searching in the current directory (in this case, /Users/boombot). The "! -user sbutler" tells it to print out any file or directory whose owner is not "sbutler" (I assume you put "boombot" here since otherwise you'd get more than three results :)

So all it's saying is that those three files aren't owned by you (they're most likely owned by "root"). All you have to do is change the ownership (the chown command) and you shouldn't have this problem again.

I'm guessing the error arrises because Finder is trying to preserve owner/group memberships. As realcountrymusic suggests, ignoring permissions on the external drive would also make the message go away (if my assumption is correct).
posted by sbutler at 10:47 PM on July 9, 2005

Response by poster: RealCountry,
I've run into the same issue on my work machine (the question stems from my home box). Both machines recieved a clean install, after which I dragged the User folder off the external HD and into the new Tiger account.

I did check the drive's Get Info screen, 'Ignore ownership on this volume' is checked.
posted by boombot at 10:51 PM on July 9, 2005

sbutler, it has to be. No need to send boombot to the command line though. It's all do-able through the Get Info command described above. If you don't know what you are doing with chown and chmod etc., be careful.
posted by realcountrymusic at 10:52 PM on July 9, 2005

Response by poster: I might also mention, two of the three results kicked back on the command provided by SButler are aliases (Library/Favorites/Documents and Pictures/iChat Icons). The other is an Adobe preference list.
posted by boombot at 10:55 PM on July 9, 2005

OK, the clean install and replacing the user folder has to be the problem here. But repairing permissions should have fixed it. Have you tried rebooting? There is some incorrectly permissioned file or directory in your user folder. The next step is beyond my ability to describe in detail. I'd try creating a folder afresh with your username on the backup drive, and copying folders one at a time into it until you found one which asked for the admin password. (Of course it might be more than one directory, and more than one file in any one directory.) I am sure there is a faster and more elegant scheme than what I would then do, which is check the permissions on each file in the stubborn directory, and if possible trash (as in move, don't delete yet) the problem files, try to copy the original user file again, and if that works then you know at least what's wrong.

There are better Mac gurus around this shop. Someone will know an easier way.
posted by realcountrymusic at 10:58 PM on July 9, 2005

Hyperjeff's OS X site lists a few third party permissions troubleshooting and repair tools, some free, here.
posted by realcountrymusic at 11:03 PM on July 9, 2005

I meant, don't you have to have at least one admin account. It was in reference to this:

Oh, sorry. Yes, of course. There has to be an admin. That's why I was wondering if boombot didn't have access to the admin account. Because in truth, what I would do in that situation is enter the admin password and keep going. But I thought perhaps BB was a user of a computer which had another administrator and didn't want to or couldn't do that.

Absolutely, someone has to be the admin. Might as well be you. Unless you're 14, download music over p2p, or like to leave ports open for the heck of it. In that case, by all means, disable your account privilegesn until you get over it.
posted by realcountrymusic at 5:59 AM on July 10, 2005

But to be clear, I understood boombot to be saying he (?) had a user account with no admin privileges, and even if he also had admin privileges, he wanted to figure out why this was happening on the user account(s) in question. Now meet sudo . . . . and let's really get the party started.
posted by realcountrymusic at 6:03 AM on July 10, 2005

Response by poster: That's exactly it, RealCountry. I'm the sole user of my G5, and have a admin account I use for system maintenance. My primary account is, as you so aptly put it, underprivileged. I could provide a password, I'd just like to understand why I need to, and then to correct the issue so that I don't need to.
posted by boombot at 8:58 AM on July 10, 2005

Perhaps go check the privileges on that user account, reset them and resave them. Then repair privileges. But now I'm just spitting in the dark.
posted by realcountrymusic at 11:39 AM on July 10, 2005

question: is there any way to pipe the results from "find . ! -user sbutler" to the chown command? I've had the same problem, and was snooping around, and it seems like i've got a bunch of files that are causing problems, and I don't want to have to change them all individually.

Thanks sbutler!
posted by Freen at 6:51 PM on July 10, 2005

Freen: pipe it to xargs like so -

find . ! -user sbutler | xargs chown -R user:group

that should do the trick. i think.
posted by soi-disant at 8:48 PM on July 10, 2005