File System Panics

If a file system detects any internal inconsistencies while it is in use, it will panic the system. If the file system is setup for UFS logging, it notifies the trans metadevice that it needs to be checked at reboot. The trans metadevice transitions itself to the "Hard Error" state. All other trans metadevices sharing the same logging device also go into the "Hard Error" state.

At reboot, fsck checks and repairs the file system and transitions the file system back to the "Okay" state. fsck does this for all trans metadevices listed in the /etc/vfstab file for the affected logging device.