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Changed permissions for "everyone" - "no access" on Macintosh HD, no boot.

Hello Everyone,



I was trying to change the permissions on my 24" iMac so that main hard drive would not be visible to everyone that could access my network. Unfortunately, I did not know that changing it would effectively lock out the computer all together. Ok, on to what I've done so far.



First, I booted with the Snow Leopard CD and repaired permissions and repaired the drive as well. Both came back with good reports. Tried to reboot and nothing. Just the gray screen of death with the perpetual wheel.



Second, I restored from a Time Machine backup from the same day I changed the permissions,but from an earlier time. It didn't work and still gave me the gray screen, but I may have been mistaken on what time I actually made the changes. I was going to try a second time, but I don't know if permissions are effected with a Time Machine restore.



Third, I tried running some commands in single user mode. /sbin/mount -uw /, /bin/chmod -R o=r,+X /, /usr/sbin/chown root:admin /, /bin/chmod 1775 /, /bin/chmod -N / I've separated them by comma's here but entered them one at a time in the command prompt. The command /bin/chmod -R o=r,+X / kicked out a bunch of errors in trying to change the permissions on the application Windows Media Player, then gave these two errors. /dev/fd/3: Not a directory, /dev/fd/4: Bad file descriptor. Then it gave a few more permissions errors on some songs. After that, I ran the rest of the commands listed above and rebooted. Again, nothing. Just the same gray screen and wheel.



I've also tried starting into safe mode. The bar comes up on the bottom of the screen but goes away, the OS just hangs at the gray screen. I've even tried running a couple sudo commands; however, I have seemed to have locked myself out of those as well.



I have many more Time Machine backup's to try but I am hesitant as I do not know if the previous permissions are attached to the backup itself, or if the changes I've made to the permissions will remain no matter what backup I restore to. I've scoured the internet in an effort to solve the problem; however, I have been unsuccessful in my attempts. It's a pretty 24" paperweight, and a nice nightlight. I liked it better as a computer though, your help would be much appreciated.

24" iMac, Mac OS X (10.6.6)

Posted on Feb 13, 2011 3:00 AM

Reply
21 replies

Jun 2, 2014 8:37 AM in response to jthedwalker

Hey, i've just set the mac HD Permission to "no acces" for everyone. The reason was to not have acces guest users from my desktop. Now i have a huge problem. My mac pro (desktop) does not boot, anyway, anyhow. Just a blue screen appear after the apple logo and round counter. The keyboard dose not respond, hardly i manged to eject dvd tray to insert a install mac osx. Problem is that doesnt boot from that disc, and I need to start the computer because I have some stuff on desktop that I must to recover. Is there any way to retrieve something from the desktop or roll back to change permissions? I read almost all posts but I cant go to "terminal" or boot from another device or eaven safe mode :( or explain how to reboot in target mode. It is possible from a pc or just from a mac? Please, any help. Thanks

Jun 2, 2014 10:57 AM in response to OnixD

No backup?


Boot into single user mode, Cmd-S at the startup chime and then enter at the root# prompt, in succession, the following commands, hitting return/enter after each. Pay careful attention to spaces and case.


mount -uw /


chown root /


chmod 1775 /


reboot


If when you did this, you hit Apply to enclosed, then all bets are off. You would have wrecked the permissions on hundreds of thousands of individual files.


And if this doesn't work, please start a new topic, since few people will read an old one, especially one that's showing solved.

Jun 2, 2014 3:52 PM in response to WZZZ

First of all, Thanks. Is the first time when I use this forum and I m not very familiar with it. Anyway, I solve the problem by reinstalling os x and admin account was not damaged at all 🙂

Unfortunately, I did not had a backup because I do not know how to do it right with TM. I use an external hdd for files but i didn't get to do the transfer because of this error.

Thanks for your support

Feb 1, 2016 3:51 PM in response to WZZZ

I was transferring files between my Macbook Air and iMac over Ethernet, noticed Macintosh HD was shared in Get Info, and thought, "why, isn't that silly?" I set the everyone permission to "NO ACCESS"... Oops....


THANKFULLY, I found this thread and performed the steps mentioned by the ever gracious WZZZ...


Boot into Single User Mode -- command-S on startup, then:

mount -uw /

chown root /

chmod 1775 /

reboot


It's 2016 and I'm running OS X El Capitan 10.11.3!

THANK YOU!!! CRISIS AVERTED!!!!

Changed permissions for "everyone" - "no access" on Macintosh HD, no boot.

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