Fix sudo on a Mac 

Sometimes the sudo command stops working for reasons beyond human understanding. When you try to sudo anything, it says: “no valid sudoers sources found”.

It happened to me twice. The first time it happened to a MacBook. I tried to make some changes to the sudoers file, but it didn’t help, and I gave up. After adding an SSD drive to my Mac Pro and moving the system to it, it happened again. Mac Pro is my main working machine, so I had to fix it this time.

Turned out the problem was with the permissions on the root directory. Presumably I’ve somehow broken them while moving my system.

I found a working solution on MacRumors forum. Here’s what you do:

  1. Restart your Mac is a single-user mode (press and hold ⌘+S during boot until you see command prompt).
  2. /sbin/fsck -fy
    check the filesystem integrity (not sure it’s necessary, but I did it anyway).
  3. /sbin/mount -wu /
    mount the root filesystem.
  4. /bin/chmod 1775 /
    fix the permissions.
  5. /bin/sync
    commit the changes to filesystem.
  6. exit

After booting to the normal Mac environment, you may also need to repair permissions with the Disk Utility.

   
Subscribe to this blog
Share
2012   Mac   solution
Popular