Change the Admin Password with Mac OS X Single User Mode
If you’re in IT, or just fixing Grandmas Mac, it’s not too uncommon to get a machine where you don’t have the admin users password. If you find yourself in this situation, you can easily change the Admin password, or any other users, simply by booting into Mac OS X‘s command line Single User Mode. I consider this to be essential knowledge for troubleshooting Macs.
Change an Admin Password in Mac OS X Single User Mode
This is a multistep process but it’s easy to follow:
- First you need to enter Single User Mode. Reboot the Mac and hold down Command+S at boot to enter into the command line.
- You’ll see a note where Mac OS X tells you that you need to run two commands in order to make filesystem changes, this is necessary so let’s handle that first
- The first command checks the Mac OS X filesystem for errors and fixes them, it can take a few minutes to run:
- The next command mounts the root Mac OS X drive as writable, allowing you to make changes to the filesystem:
- After the filesystem is mounted, you can reset any users password using the following command:
- You’ll need to enter the new password twice to reset and confirm the changes
mount -uw /
Note that a password will not be visibly typed when using the ‘passwd’ command, it looks as if nothing is being entered at all. That is standard practice in the command line world.
Changing Admin Password in OS X Lion, Mountain Lion, and later
For users with OS X 10.7.3 and later, including OS X 10.8+ Mountain Lion, there may need to be an additional step to load open directory. If you have issues with the above approach, try the following command sequence with newer versions of Mac OS X. Note the primary difference is using ‘launchctl’ between mounting the drive and changing the password:
#1 fsck -fy
#2 mount -uw /
#3 launchctl load /System/Library/LaunchDaemons/com.apple.opendirectoryd.plist
#4 passwd username
The password should now change as expected, where you can then reboot and use the admin user account as expected. Rebooting is possible through the command line by by typing:
Or by using the standard manual restart methods of keyboard shortcuts, shutdown, or holding down the power button. On the next boot the changed admin password will be usable as anticipated.
Don’t know the admin username? No problem
If you’re fixing someones machine and you don’t know the username to reset, just look in /Users with:
Here you’ll see at least three items, .localized, Shared, and a username. The username is what you’ll want to change with the passwd command.
After the password is reset and confirmed, you can exit out of Single User Mode by typing exit or reboot. The Mac will now boot as usual and you’ll have access to the machine with the new password.
This is an easier and faster method than the approach taken for resetting lost passwords or using the Mac OS X boot DVD, because it’s changing an existing root users password rather than creating a new admin user account. Both work fine though, so you can use whatever method you’d like.
You can use the same approach to navigate around a sleep/wake lock screen, although you’ll obviously have to reboot the Mac meaning you will miss whatever is currently on the users desktop.