If you get an error message saying a filesystem is corrupt run the fsck(1M) command. The fsck command can be used to check the integrity of any mounted filesystem, and runs automatically on the root filesystem whenever the system is rebooted following an abnormal shutdown. The fsck command can also be used to repair a corrupted filesystem, if repair is possible.
See ``Solving filesystem problems'' for an in-depth discussion about using fsck with various types of filesystems.