WARNING: You should
never use the disklabel -c option unless you wish to completely replace the disklabel. If I've understood correctly, that is something you are trying specifically to avoid doing.
As usual, you have failed to post sufficient information, so I have to just guess:
- You have a single drive, on which there is a 19 GB /tmp you would like to reduce in size,
- You do not understand the error messages you've received from disklabel(8).
- Your problem is caused by trying to change or delete the /tmp partition from the disklabel while /tmp is mounted.
- You do not know how to proceed.
If I've guessed incorrectly, it is because you haven't provided necessary information, such as the current disklabel, your intended disklabel, or the complete text of the error message.
Based on my guesses, and only my guesses, you must ensure /tmp is dismounted before attempted to change its size, or to delete and recreate it. Choose one of these methods:
- Boot in single-user mode, or
- Boot the RAMDISK kernel, or
- Stop all processes using /tmp and then dismount it.