e2fsck.conf(5)               File Formats Manual              e2fsck.conf(5)

NAME         top

       e2fsck.conf - Configuration file for e2fsck

DESCRIPTION         top

       e2fsck.conf is the configuration file for e2fsck(8).  It controls the
       default behavior of e2fsck(8) while it is checking ext2, ext3, or
       ext4 filesystems.

       The e2fsck.conf file uses an INI-style format.  Stanzas, or top-level
       sections, are delimited by square braces: [ ].  Within each section,
       each line defines a relation, which assigns tags to values, or to a
       subsection, which contains further relations or subsections.  An
       example of the INI-style format used by this configuration file
       follows below:

                 tag1 = value_a
                 tag1 = value_b
                 tag2 = value_c

            [section 2]
                 tag3 = {
                      subtag1 = subtag_value_a
                      subtag1 = subtag_value_b
                      subtag2 = subtag_value_c
                 tag1 = value_d
                 tag2 = value_e

       Comments are delimited by a semicolon (';') or a hash ('#') character
       at the beginning of the comment, and are terminated by the end of
       line character.

       Tags and values must be quoted using double quotes if they contain
       spaces.  Within a quoted string, the standard backslash
       interpretations apply: "\n" (for the newline character), "\t" (for
       the tab character), "\b" (for the backspace character), and "\\" (for
       the backslash character).

       The following stanzas are used in the e2fsck.conf file.  They will be
       described in more detail in future sections of this document.

              This stanza contains general configuration parameters for
              e2fsck's behavior.

              This stanza allows the administrator to reconfigure how e2fsck
              handles various filesystem inconsistencies.

              This stanza controls when e2fsck will attempt to use scratch
              files to reduce the need for memory.

THE [options] STANZA         top

       The following relations are defined in the [options] stanza.

              If this relation is set to a boolean value of true, then if
              the user interrupts e2fsck using ^C, and the filesystem is not
              explicitly flagged as containing errors, e2fsck will exit with
              an exit status of 0 instead of 32.  This setting defaults to

              Unfortunately, due to Windows' unfortunate design decision to
              configure the hardware clock to tick localtime, instead of the
              more proper and less error-prone UTC time, many users end up
              in the situation where the system clock is incorrectly set at
              the time when e2fsck is run.

              Historically this was usually due to some distributions having
              buggy init scripts and/or installers that didn't correctly
              detect this case and take appropriate countermeasures.
              Unfortunately, this is occasionally true even today, usually
              due to a buggy or misconfigured virtualization manager or the
              installer not having access to a network time server during
              the installation process.  So by default, we allow the
              superblock times to be fudged by up to 24 hours.  This can be
              disabled by setting accept_time_fudge to the boolean value of
              false.  This setting defaults to true.

              The e2fsck(8) program has some heuristics that assume that the
              system clock is correct.  In addition, many system programs
              make similar assumptions.  For example, the UUID library
              depends on time not going backwards in order for it to be able
              to make its guarantees about issuing universally unique ID's.
              Systems with broken system clocks, are well, broken.  However,
              broken system clocks, particularly in embedded systems, do
              exist.  E2fsck will attempt to use heuristics to determine if
              the time can not be trusted; and to skip time-based checks if
              this is true.  If this boolean is set to true, then e2fsck
              will always assume that the system clock can not be trusted.

              This boolean relation is an alias for accept_time_fudge for
              backwards compatibility; it used to be that the behavior
              defined by accept_time_fudge above defaulted to false, and
              buggy_init_scripts would enable superblock time field to be
              wrong by up to 24 hours.  When we changed the default, we also
              renamed this boolean relation to accept_time_fudge.

              This boolean relation controls whether or not e2fsck(8) will
              offer to clear the test_fs flag if the ext4 filesystem is
              available on the system.  It defaults to true.

              This boolean relation controls whether or not the interval
              between filesystem checks (either based on time or number of
              mounts) should be doubled if the system is running on battery.
              This setting defaults to true.

              When e2fsck(8) repacks a indexed directory, reserve the
              specified percentage of empty space in each leaf nodes so that
              a few new entries can be added to the directory without
              splitting leaf nodes, so that the average fill ratio of
              directories can be maintained at a higher, more efficient
              level.  This relation defaults to 20 percent.

              If this boolean relation is true, trade off using memory for
              speed when checking a file system with a large number of hard-
              linked files.  The amount of memory required is proportional
              to the number of inodes in the file system.  For large file
              systems, this can be gigabytes of memory.  (For example a 40TB
              file system with 2.8 billion inodes will consume an additional
              5.7 GB memory if this optimization is enabled.)  This setting
              defaults to false.

              If the log_filename relation contains a relative pathname,
              then the log file will be placed in the directory named by the
              log_dir relation.

              This relation contains an alternate directory that will be
              used if the directory specified by log_dir is not available or
              is not writeable.

              If this boolean relation is true, them if the directories
              specified by log_dir or log_dir_fallback are not available or
              are not yet writeable, e2fsck will save the output in a memory
              buffer, and a child process will periodically test to see if
              the log directory has become available after the boot sequence
              has mounted the requiste file system for reading/writing.
              This implements the functionality provided by logsave(8) for
              e2fsck log files.

              This relation specifies the file name where a copy of e2fsck's
              output will be written.   If certain problem reports are
              suppressed using the max_count_problems relation, (or on a
              per-problem basis using the max_count relation), the full set
              of problem reports will be written to the log file.  The
              filename may contain various percent-expressions (%D, %T, %N,
              etc.) which will be expanded so that the file name for the log
              file can include things like date, time, device name, and
              other run-time parameters.  See the LOGGING section for more

              This relation specifies the maximum number of problem reports
              of a particular type will be printed to stdout before further
              problem reports of that type are squelched.  This can be
              useful if the console is slow (i.e., connected to a serial
              port) and so a large amount of output could end up delaying
              the boot process for a long time (potentially hours).

              If this boolean relation is true, do not offer to optimize the
              extent tree by reducing the tree's width or depth.  This
              setting defaults to false.

              Use this percentage of memory to try to read in metadata
              blocks ahead of the main e2fsck thread.  This should reduce
              run times, depending on the speed of the underlying storage
              and the amount of free memory.  There is no default, but see
              readahead_kb for more details.

              Use this amount of memory to read in metadata blocks ahead of
              the main checking thread.  Setting this value to zero disables
              readahead entirely.  By default, this is set the size of two
              block groups' inode tables (typically 4MiB on a regular ext4
              filesystem); if this amount is more than 1/50th of total
              physical memory, readahead is disabled.

              If this boolean relation is true, e2fsck will print the file
              system features as part of its verbose reporting (i.e., if the
              -v option is specified)

              If this boolean relation is true, e2fsck will run as if the
              options -tt are always specified.  This will cause e2fsck to
              print timing statistics on a pass by pass basis for full file
              system checks.

              If this boolean relation is true, e2fsck will run as if the
              option -v is always specified.  This will cause e2fsck to
              print some additional information at the end of each full file
              system check.

THE [problems] STANZA         top

       Each tag in the [problems] stanza names a problem code specified with
       a leading "0x" followed by six hex digits.  The value of the tag is a
       subsection where the relations in that subsection override the
       default treatment of that particular problem code.

       Note that inappropriate settings in this stanza may cause e2fsck to
       behave incorrectly, or even crash.  Most system administrators should
       not be making changes to this section without referring to source

       Within each problem code's subsection, the following tags may be

              This relation allows the message which is printed when this
              filesystem inconsistency is detected to be overridden.

              This boolean relation overrides the default behavior
              controlling whether this filesystem problem should be
              automatically fixed when e2fsck is running in preen mode.

              This integer relation overrides the max_count_problems
              parameter (set in the options section) for this particular

       no_ok  This boolean relation overrides the default behavior
              determining whether or not the filesystem will be marked as
              inconsistent if the user declines to fix the reported problem.

              This boolean relation overrides whether the default answer for
              this problem (or question) should be "no".

              This boolean relation overrides the default behavior
              controlling whether or not the description for this filesystem
              problem should be suppressed when e2fsck is running in preen

              This boolean relation overrides the default behavior
              controlling whether or not the description for this filesystem
              problem should be suppressed when a problem forced not to be
              fixed, either because e2fsck is run with the -n option or
              because the force_no flag has been set for the problem.

              This boolean option, if set to true, forces a problem to never
              be fixed.  That is, it will be as if the user problem responds
              'no' to the question of 'should this problem be fixed?'.  The
              force_no option even overrides the -y option given on the
              command-line (just for the specific problem, of course).

              This boolean option, it set to true, marks the problem as one
              where if the user gives permission to make the requested
              change, it does not mean that the file system had a problem
              which has since been fixed.  This is used for requests to
              optimize the file system's data structure, such as pruning an
              extent tree.

THE [scratch_files] STANZA         top

       The following relations are defined in the [scratch_files] stanza.

              If the directory named by this relation exists and is
              writeable, then e2fsck will attempt to use this directory to
              store scratch files instead of using in-memory data

              If this relation is set, then in-memory data structures be
              used if the number of directories in the filesystem are fewer
              than amount specified.

              This relation controls whether or not the scratch file
              directory is used instead of an in-memory data structure for
              directory information.  It defaults to true.

       icount This relation controls whether or not the scratch file
              directory is used instead of an in-memory data structure when
              tracking inode counts.  It defaults to true.

LOGGING         top

       E2fsck has the facility to save the information from an e2fsck run in
       a directory so that a system administrator can review its output at
       their leisure.  This allows information captured during the automatic
       e2fsck preen run, as well as a manually started e2fsck run, to be
       saved for posterity.  This facility is controlled by the
       log_filename, log_dir, log_dir_fallback, and log_dir_wait relations
       in the [options] stanza.

       The filename in log_filename may contain the following percent-
       expressions that will be expanded as follows.

       %d     The current day of the month

       %D     The current date; this is a equivalent of %Y%m%d

       %h     The hostname of the system.

       %H     The current hour in 24-hour format (00..23)

       %m     The current month as a two-digit number (01..12)

       %M     The current minute (00..59)

       %N     The name of the block device containing the file system, with
              any directory pathname stripped off.

       %p     The pid of the e2fsck process

       %s     The current time expressed as the number of seconds since
              1970-01-01 00:00:00 UTC

       %S     The current second (00..59)

       %T     The current time; this is equivalent of %H%M%S

       %u     The name of the user running e2fsck.

       %U     This percent expression does not expand to anything, but it
              signals that any following date or time expressions should be
              expressed in UTC time instead of the local timzeone.

       %y     The last two digits of the current year (00..99)

       %Y     The current year (i.e., 2012).

EXAMPLES         top

       The following recipe will prevent e2fsck from aborting during the
       boot process when a filesystem contains orphaned files.  (Of course,
       this is not always a good idea, since critical files that are needed
       for the security of the system could potentially end up in
       lost+found, and starting the system without first having a system
       administrator check things out may be dangerous.)

                 0x040002 = {
                      preen_ok = true
                      description = "@u @i %i.  "

       The following recipe will cause an e2fsck logfile to be written to
       the directory /var/log/e2fsck, with a filename that contains the
       device name, the hostname of the system, the date, and time: e.g.,
       "e2fsck-sda3.server.INFO.20120314-112142".  If the directory
       containing /var/log is located on the root file system which is
       initially mounted read-only, then the output will be saved in memory
       and written out once the root file system has been remounted
       read/write.   To avoid too much detail from being written to the
       serial console (which could potentially slow down the boot sequence),
       only print no more than 16 instances of each type of file system

                 max_count_problems = 16
                 log_dir = /var/log/e2fsck
                 log_filename = e2fsck-%N.%h.INFO.%D-%T
                 log_dir_wait = true

FILES         top

              The configuration file for e2fsck(8).

SEE ALSO         top


COLOPHON         top

       This page is part of the e2fsprogs (utilities for ext2/3/4
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E2fsprogs version 1.43.6         August 2017                  e2fsck.conf(5)

Pages that refer to this page: e2fsck(8)