e2fsck.conf(5) — Linux manual page

NAME | DESCRIPTION | THE [options] STANZA | THE [defaults] STANZA | THE [problems] STANZA | THE [scratch_files] STANZA | LOGGING | EXAMPLES | FILES | SEE ALSO | COLOPHON

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 file systems.

       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:

            [section1]
                 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.

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

       [defaults]
              Contains relations which define the default parameters
              used by e2fsck(8).  In general, these defaults may be
              overridden by command-line options provided by the user.

       [problems]
              This stanza allows the administrator to reconfigure how
              e2fsck handles various file system inconsistencies.

       [scratch_files]
              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.

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

       accept_time_fudge
              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.

       broken_system_clock
              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.

       buggy_init_scripts
              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.

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

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

       indexed_dir_slack_percentage
              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.

       inode_count_fullmap
              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.

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

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

       log_dir_wait
              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 writable, 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 requested file system for
              reading/writing.  This implements the functionality
              provided by logsave(8) for e2fsck log files.

       log_filename
              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
              details.

       max_count_problems
              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).

       no_optimize_extents
              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.

       problem_log_filename
              This relation specifies the file name where a log of
              problem codes found by e2fsck be written.  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 details.

       readahead_mem_pct
              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.

       readahead_kb
              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 file system); if this amount is more than
              1/50th of total physical memory, readahead is disabled.

       report_features
              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)

       report_time
              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.

       report_verbose
              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 [defaults] STANZA         top

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

       undo_dir
              This relation specifies the directory where the undo file
              should be stored.  It can be overridden via the
              E2FSPROGS_UNDO_DIR environment variable.  If the directory
              location is set to the value none, e2fsck will not create
              an undo file.

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 code.

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

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

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

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

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

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

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

       no_nomsg
              This boolean relation overrides the default behavior
              controlling whether or not the description for this file
              system 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.

       force_no
              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).

       not_a_fix
              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.

       directory
              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
              structures.

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

       dirinfo
              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
              timezone.

       %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 file system 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.)

            [problems]
                 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 corruption.

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

FILES         top

       /etc/e2fsck.conf
              The configuration file for e2fsck(8).

SEE ALSO         top

       e2fsck(8)

COLOPHON         top

       This page is part of the e2fsprogs (utilities for ext2/3/4
       filesystems) project.  Information about the project can be found
       at ⟨http://e2fsprogs.sourceforge.net/⟩.  It is not known how to
       report bugs for this man page; if you know, please send a mail to
       man-pages@man7.org.  This page was obtained from the project's
       upstream Git repository
       ⟨git://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git⟩ on
       2021-08-27.  (At that time, the date of the most recent commit
       that was found in the repository was 2021-08-22.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

E2fsprogs version 1.46.4       August 2021                e2fsck.conf(5)

Pages that refer to this page: e2fsck(8)