fsck Command – Check & Repair Linux & Unix File Systems

Initialization Phase

In the initialization phase fsck sets up certain tables and open certain files. The following messages relate to error conditions resulting from command-line options, memory requests, the opening of files, the status of files, filesystem size checks, and the creation of the scratch file during different phases of fsck process.
fsck error messages, warning messages and responses for Initialization Phase.

i.1) Can’t open checklist file: F

The file system checklist or default file F (usually /etc/vfstab) cannot be opened for reading. When this occurs, fsck terminates. Check the access modes of F

i.2) Can’t stat root

fsck’s request for statistics about the root directory failed. This is very rare. When it does happen, fsck terminates.

i.3) Can’t stat F

Can’t make sense out of name F
fsck’s request for statistics about the file system F failed. When fsck is running interactively, it ignores this
file system and continues checking the next file system given. Check the access modes of F

i.4) Can’t open F

fsck’s attempt to open the file system F failed. When running interactively, it ignores this
file system and continues checking the next file system given. Check the access modes of F.

i.5) F: (NO WRITE)

Either the -n flag was specified or fsck’s attempt to open the file system F for writing failed. When fsck is running interactively, all the diagnostics are printed out, but fsck does not attempt to fix anything.

i.6) file is not a block or character device; OK

The user has given fsck the name of a regular file by mistake. Check the type of the file specified.
Possible responses to the OK prompt are:

YES – Ignore this error condition.

NO – Ignore this file system and continue checking the next file system given.

i.7) UNDEFINED OPTIMIZATION IN super block (SET TO DEFAULT

The super block optimization parameter is neither OPT_TIME nor OPT_SPACE.

Possible responses to the SET TO DEFAULT prompt are:

YES – Set the super block to request optimization to minimize running time of the system. (If optimization to minimize disk space use is desired, it can be set using tunefs(1M).

NO – Ignore this file system and continue checking the next file system given.

i.8) IMPOSSIBLE MINFREE=D IN super block (SET TO DEFAULT)

The super block minimum space percentage is greater than 99 percent or less than 0 percent.

Possible responses to the SET TO DEFAULT prompt are:

YES – Set the MINFREE parameter to ten percent. (If some other percentage is desired, it can be set using tunefs(1M).)

NO – Ignore this error condition.

i.9) MAGIC NUMBER WRONG

NCG OUT OF RANGE
CPG OUT OF RANGE
NCYL DOES NOT JIVE WITH NCG*
CPG SIZE PREPOSTEROUSLY LARGE
TRASHED VALUES IN SUPER BLOCK

This is followed by the message:
F: BAD SUPER BLOCK: B
USE -b OPTION TO FSCK TO SPECIFY LOCATION OF AN ALTERNATE SUPER-BLOCK TO SUPPLY NEEDED INFORMATION;

An alternative super block must be selected from among the available copies. Choose an alternative
super block by calculating its offset. Specifying block 32 is a good first choice.

i.10) INTERNAL INCONSISTENCY: M

fsck has had an internal panic, whose message is M.

i.11) CAN NOT SEEK: BLK B (CONTINUE)

fsck’s request to move to a specified block number B in the file system failed. If it does happen.

Possible responses to the CONTINUE prompt are:

YES – Attempt to continue running the file system check. (Note that the problem often persists.) This error condition prevents a complete check of the
file system. A second run of fsck should be made to recheck the filesystem. If the block was part of the virtual memory buffer cache, fsck terminates with this message : Fatal I/O error

NO – Terminate the program

i.12) CAN NOT READ: BLK B (CONTINUE)

fsck’s request to read a specified block number B in the file system failed.
if it does happen
Possible responses to the CONTINUE prompt are:

YES – Attempt to continue running the file system check. fsck retries the read and prints out the message:
THE FOLLOWING SECTORS COULD NOT BE READ: N – where N indicates the sectors that could not be read.

If fsck ever tries to write back one of the blocks on which the read failed, it prints the message:
WRITING ZERO’ED BLOCK N TO DISK – where N indicates the sector that was written with zero’s.

If the disk is experiencing hardware problems, the problem will persist.
This error condition prevents a complete check of the file system and a second run of fsck should be made to recheck the filesystem. If the block was part of the virtual memory buffer cache, fsck terminates with the message – Fatal I/O error

NO – Terminate the program.

i.13) CAN NOT WRITE: BLK B (CONTINUE)

fsck’s request to write a specified block number B in the file system failed. The disk is write-protected; check the write-protect lock on the drive.

Possible responses to the CONTINUE prompt are:

YES – Attempt to continue to run the file system check. The write operation will be retried. Sectors that could not be written are indicated by the message: THE FOLLOWING SECTORS COULD NOT BE WRITTEN: N – where N indicates the sectors that could not be written. If the disk is experiencing hardware problems, the problem will persist. This error condition prevents a complete check of the file system. A second run of fsck should be made to recheck this filesystem. If the block was part of the virtual memory buffer cache, fsck terminates with the message: Fatal I/O error

NO – Terminate the program.

i.14) bad inode number DDD to ginode

An internal error was caused by an attempt to read non-existent inode DDD.
This error causes fsck to exit.

Initialization Phase
NEXT>>** phase 1 – Check Blocks and Sizes
** phase 2 – Check Pathnames
** phase 3 – Check Connectivity
** phase 4 – Check Reference Counts
** phase 5 – Check Cylinder Groups
cleanup phase