Sun Microsystems Sun Workstation 100U System Manager's Manual page 185

FSCK(8 )
MAINTENANCE COMMANDS FSCK(8)
NAME
fsck - file system consistency check and interactive repair
SYNOPSIS
I
eteltack
-p [ filesystem ... )
letcltack [ -b
block# ) [
-y ) [
-n ) [
filesystem ) ...
DESCRIPTION
30
The first form of jsck preens a standard set of filesystems or the specified file systems. It is nor-
mally used in the script
lete/rc
during automatic reboot. In this case jsck reads the table
letellatab
to determine which file systems to check. It uses the information there to inspect
groups of disks in parallel taking maximum advantage of i/o overlap to check the file systems as
quickly as possible. Normally, the root file system will be checked on pass 1, other "root" ("a"
partition) file systems on pass 2, other small file systems on separate passes (e.g. the "d" file sys-
tems on pass 3 and the "e" file systems on pass 4), and finally the large user file systems on the
last pass, e.g. pass 5. A pass number of 0 in fstab causes a disk to not be checked; similarly parti-
tions which are not shown as to be mounted
"rw"
or "ro" are not checked.
The system takes care that only a restricted class of innocuous inconsistencies can happen unless
hardware or software failures intervene. These are limited to the following:
Unreferenced inodes
Link counts in inodes too large
. Missing blocks in the free list
Blocks in the free list also in files
Counts in the super-block wrong
These are the only inconsistencies which Isck with the -p option will correct; if it encounters
other inconsistencies, it exits with an abnormal return status and an automatic reboot will then
fail. For each corrected inconsistency one or more lines will be printed identifying the file system
on which the correction will take place, and the nature or the correction. Arter successrully
correcting a file system, jsck will print the number of files on that file system and the number of
used and free blocks.
Without the -p option, Isck audits and interactively repairs inconsistent conditions for file sys-
tems. If the file system is inconsistent the operator is prompted for concurrence before each
correction is attempted. It should be noted that a number of the corrective actions which are nO.t
fixable under the -p option will.result in some loss of data. The amount and severity of data lost
may be determined from the diagnostic output. The default action for each consistency correc-
tion is to wait for the operator to respond 7- or
no.
If the operator does not have write permis-
sion jsck will default to a -n action.
Fackhas more consistency checks than its predecessors check, dcheck, Icheck, and icheck com-
bined.
The following Bags are interpreted by Jack.
-b
Use the block specified immediately after the Bag as the super block lor the6lesystem.
Block 32 is always an alternate superblock.
-y
Assume a yes response to all questions asked by lack; this should be used withll'eatcau-
tion as this is a free license to continue alter essentially unlimited trouble has beenencoun-
teredo
-n Assume a no response
to
all questions asked by lack; do not open the file system lor writ-
ing.
If no filesystems are given ·to !8c1:
then a derault list or file systems is read rrom the file
I
etc/fatab.
Last change: 4 February 1983
Sun Release 1.1