fsck – Check & Repair Unix and Linux File Systems

Phase 5: Check Cylinder Groups

(ufs file system only)
This phase checks the free-block and used-inode maps. It reports error conditions resulting from:

    1. Allocated inodes missing from used-inode maps
    2. Free blocks missing from free-block maps
    3. Free inodes in the used-inode maps
    4. Incorrect total free-block count
    5. Incorrect total used inode count

fsck error messages, warning messages and responses for Phase 5 – Check Cylinder Groups.

5.1) BLK(S) MISSING IN BIT MAPS (SALVAGE)

A cylinder group block map is missing some free blocks. During preening, the maps are reconstructed.

Possible responses to the SALVAGE prompt are:

YES Reconstruct the free block map.

NO – Don’t salvage

5.2) CG C: BAD MAGIC NUMBER

The magic number of cylinder group C is wrong. This usually indicates that the cylinder group maps have been destroyed. When running interactively, the cylinder group is marked as needing reconstruction. This error is fatal if the file system is being
repaired.

5.3) SUMMARY INFORMATION BAD (SALVAGE)

The summary information was found to be incorrect. When preening, the summary information is recomputed.

Possible responses to the SALVAGE prompt are:

YES Reconstruct the summary information.

NO Ignore this error condition.

5.4) FREE BLK COUNT(S) WRONG IN super block (SALVAGE)

The super block free block information was found to be incorrect. When preening, the
super block free block information is recomputed.

Possible responses to the SALVAGE prompt are:

YES Reconstruct the super block free block information.
NO Ignore this error condition.

Initialization Phase
** phase 1 – Check Blocks and Sizes
** phase 2 – Check Pathnames

** phase 3 – Check Connectivity

** phase 4 – Check Reference Counts
** phase 5 – Check Cylinder Groups
NEXT>>cleanup phase

Pages: 1 2 3 4 5 6 7 8

One Response to fsck – Check & Repair Unix and Linux File Systems

  1. Thanks for the nice tutorial. Great job!

Leave a Reply

Your email address will not be published. Required fields are marked *