If /var is a separate file system on the machine and is not yet mounted, mount it now. If the file system containing /var is mounted read-only, remount it read-write with a command similar to this:
Then type Control-D
and try to bring up the system multi-user. If that fails, the root file system is probably corrupted. Run fsck(1M)
on the root file system, halt the
machine, power cycle the CPU, and wait for the system to reboot. Should this problem still occur, restore the root file system from backup tapes, or re-install the system from net or CD-ROM to replace the root file system.