Changed permissions now Mac wont start

Try this:

After the Command-S startup, type the following on the command prompts, allowing time for each to do its thing:
/sbin/fsck -y<return>
/sbin/mount -uw /<return>
/sbin/autodiskmount -va<return>
/usr/sbin/diskutil repairPermissions /

And, when one is sure it's all done, type:
reboot<return>

Click to expand...

shoreyduke said:

Thank you for your time Michael. I did exactly (word for word) as you suggested but the return response on the last line was ..
“-sh: /user/sbin/diskutil: No such file or directory”

I have been trying this fix ..
• Boot into single-user mode (boot while holding down CMD-S)
• Follow the on-screen instructions to mount the file system as read-write (a fsck/mount command followed by a mount command)
• Type the following: "chmod o+r /" followed by "chmod o+x /"
• Type "exit" to leave single user mode and complete the boot sequence.
but cant seem to mount the file system as read-write .. it says it is (hfs, local, read-only, journaled) .. So I presume the commands cant change anything in the system??

Click to expand...

First of all, type "which diskutil" and you should get back /usr/sbin/diskutil. If not, use whatever path really comes back. Second of all, you might have to use something other than "/" as the target to repair permissions. Perhaps something like "/usr/sbin/diskutil repairPermissions /Volumes/Somedisk" where Somedisk is the disk you booted from and are trying to repair. More here...

There's a discussion on the topic here, but it's from a few years ago. Still, they mention and recommend an utility by the name of AppleJack

Also, which folder's permissions did you modify, what's the name of it?

Given that you don't have your system disk with you, your options are limited.

Perhaps a trip to the apple store may be in order

DiskWarrior supports repairing disk permissions, so you can give that a try if you have access to it. Data Rescue does not, it's designed only to retrieve files and leave the hard drive untouched.

jW

maflynn said:

Given that you don't have your system disk with you, your options are limited.

Perhaps a trip to the apple store may be in order

Click to expand...

I have to agree. It sounds like the OP picked / and applied rwxr x r x to his entire Macintosh HDD. On the surface this might seem safe but it's the equivalent of taking a bazooka to Macintosh HDD and the best way to recover would be a wipe and install (provided his data is backed up) .

This makes me appreciate why Apple is trying to make OS X more like iOS. Unless you jailbreak, there is no way to make an iPhone useless by applying this sort of blunt force trauma.

The good news is that OS X is Unix underneath. The bad news is that there are so many permissions to repair, I can't imagine the OP stumbling upon the right combination of permissions from single user mode. To me this would require a "snapshot" of a working Macintosh HD running 10.6 that listed permissions for every folder on the system. It would be something like a recursive "ls -RF / > /allfiles.txt" Of course the users folder should be removed from this file as you don't care about the users' folder on your friend's Mac.

You could then go through the list, focusing on folders like /bin, /sbin, /Applications, /Library, etc changing permissions on your Mac to look like those in a known good allfiles.txt from a friend's working OS 10.6 Mac.

shoreyduke said:

OH GOSH !!! ... How could such a big mess arise from just one click?
I am not technical .. but for Apple to allow the loss of an entire computer with just a click of the mouse !!! It would be harder for me to have formatted the drive .. at least there are a few steps involved and a WARNING !!!
Granted it was my stupidity and ignorance.....
Thank you all for your help, it was greatly appreciated.

Click to expand...

Really a single click?

anyways, how about downloading the Lion Recovery Assistant here: http://support.apple.com/kb/DL1433?viewlocale=en_US&locale=en_US

I know you are not running Lion, but if you have access to another Mac, you could make a bootable USB thumb drive and boot from it. On it is a Disk Utility, and you can do a repair permissions. . . . Yes you are not running Lion, but maybe it would fix enough permissions to make your machine bootable again, and then run repair permissions from your booted machine????? Just a thought.

Took more than a single click, messing about in the command shell can cause all sorts of havoc.

I accidentally changed the permissions on a disk

If the disk in question is your Mac OS X startup disk and your computer stops starting up at the blue screen, restart with the Command and S keys held down, and enter the following commands:

mount -uw /
chown root /
chmod 1775 /
exit

Enjoy!!!!
Works 100%[/B]

shoreyduke said:

Thanks all for your help.
I have managed to make a boot cd with Lion recovery and am able to start up and run disk utilities. The problem is that Disk Utilities repair permissions is Greyed out.
I believe this is because Disk util has to run off the reive to be repaired.

Click to expand...

Repair Permissions only works on a disk with an installed system, if that system has a /Library/Receipts folder. RP is NOT good enough to fix a major hose of permissions across the entire disk.

You need to reinstall the OS.

And for the record, don't manually change the permissions recursively. Don't give yourself read-write access to every folder: you are not supposed to have access everywhere. If you need to tinker with system folders, then there are ways of doing that. You'll excuse me if I suggest that your current level of skill is not quite at the point where should need to start interfering with system folders.

If there is something you particularly want to achieve, ask here, and people can give you some pointers.

I remember when I was working we had smart-a** new employees who supposedly had CS degrees and knew *NIX forward and backwards and they would come in and monkey around to "make it work better" and wind up with unbootable systems. It certainly deflated their oversize egos.

When you start monkeying around with permissions, you run down a dangerous road. It is not a bug in OSx.

dj-katchey said:

If the disk in question is your Mac OS X startup disk and your computer stops starting up at the blue screen, restart with the Command and S keys held down, and enter the following commands:

mount -uw /
chown root /
chmod 1775 /
exit

Enjoy!!!!
Works 100%[/B]

Click to expand...

Thank you for saving my (vegan) bacon! I stupidly removed "everyone" access from my boot volume (even though it had read_only, it scared me that "anyone" could read it). Searched everywhere for a solution, and this fixed it instantly. Thank You!!!

T*h* A* N*K* Y 0 U !

my comps been down for a couple days , just found this thread and worked great!





thank you again ebernet & dj-katchey


well........ never mind ...... let me in but same stuff when i restarted...............

Thank You!!!!

dj-katchey said:

If the disk in question is your Mac OS X startup disk and your computer stops starting up at the blue screen, restart with the Command and S keys held down, and enter the following commands:

mount -uw /
chown root /
chmod 1775 /
exit

Enjoy!!!!
Works 100%[/B]

Click to expand...

I changed my permissions for "everyone" on my hard drive, not knowing the outcome would be my MacBook pro 10.9.5 would be frozen on the grey screen (not bringing up the login page).

Your advice worked great. I just wanted to take the time to say thank you and that I think you are wonderful.