Turns out you can!
http://www.jeremycole.com/blog/2012/10/10/how-to-remotely-run-disk-repair-fsck-on-os-x/
But the article fails to tell you how you set the whole thing back after you're done, thus avoiding the user having to type in "exit" at a DOS looking prompt every time she/he wants to use his computer.
So here's my take on the manual. To enable single user, and make the Mac run fsck at boot; do the folllowing:
- Open up the Terminal / Utilities folder.
- type: cd .. and hit return a couple of times
- type: sudo su
- then type: sudo su -
- then type: nvram boot-args="s" (this sets the boot type to single user boot, you can revert this by typing: nvram boot-args="")
- then type: sudo nano /etc/bashrc
- then copy paste this block of text at the end of the file
singleuser=`sysctl -n kern.singleuser`
if [[ $singleuser -eq 1 ]]; thennvram boot-args=""/sbin/fsck -fyrebootelseecho Not in single user modefi
- You wanna save the changes by hitting CTLR and O to do a write out. Hit enter.
- And then restart.
If you wanna revert the process, then remote log in after the Mac has restarted automatically, do all the steps again, but remove the block of text you just added, and change the start up mode from single user mode, to normal by removing the S as described in step 5.