Checking and Repairing File Systems
In some cases an improper shutdown might cause damage to the file systems. The fsck command checks the file systems for consistency on booting. In addition, the fsck command also performs automatic and interactive correction of the problems detected during booting. The S01Mountfsys script in the /etc/rc2.d directory calls the mountall command and runs fsck on all file systems with fsck pass field in the /etc/vfstab file set above zero. This is one of the several startup scripts the system executes on booting prior to entering the multi-user state.
The mountall command used during booting invokes the fsck command to check and repair the file systems. However, two file systems on the same disk are not checked ...