Start up disk full--computer will not boot.

Question

Our Mac gives a "start up disk full" error message and freezes on the blue screen after the password login.    Resetting did no good, and entering safe mode only allows it go one step further but without any icons.   Unfortunately, we are traveling overseas and do not have a boot disk to use.    Is there a way to boot the computer, with a full start up disk, in order to resolve the issue without using a separate boot disk?

Answer 1

If you have files on the drive you can delete then you can try this:
Boot into single-user mode by holding down the COMMAND and S keys until the computer starts up to a black screen with white type. Once it stops scrolling you should see a prompt with the cursor. Enter the following:
/sbin/fsck -fy
Press RETURN. If you receive a message that says "***** FILE SYSTEM WAS MODIFIED *****" then re-run the command until you receive a message that says "** The volume (name_of_volume) appears to be OK."  If you re-run the command more than seven times and do not get the OK message, then the drive cannot be repaired this way. If you were successful then enter:
/sbin/mount -uw /
cd /Users/username
Replace "username" with your admin account's username or shortname. Press RETURN after each command line.
You may navigate into any one of your folders located in the Home folder which include:
Desktop
Documents
Downloads
Movies
Music
Pictures
by using the 'cd' command. For example, to move into your Documents folder:
cd Documents
ls -al
This moves you into the Documents folder then lists the contents of the folder. Press RETURN after each command line.
To return to your Home folder enter:
cd ..
which moves you up one level in the hierarchy. To delete a file enter:
rm -rf "filename"
where "filename" is the name of the file you want to delete. For a whole folder it's the same command only use the folder's name instead of the file's name. The quotes are use for names that have spaces in them.
If you are able to delete some large files this will free up space on your hard drive.
To restart the computer normally enter:
reboot
Be careful to enter commands correctly because in single-user mode you can permanently screw things up if you aren't careful what commands you enter. I suggest you print this out so you will have everything at your fingertips for verification.
Alternatively, find an Apple retailer and see if they will fix things for you, perhaps install a larger hard drive.