e2fsck.conf(5) manual page
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e2fsck.conf - Configuration file for e2fsck
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:
[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.
- [problems]
- This
stanza allows the administrator to reconfigure how e2fsck handles various
filesystem inconsistencies.
- [scratch_files]
- This stanza controls when e2fsck
will attempt to use scratch files to reduce the need for memory.
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 filesystem 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 filesystem is available
on the system. It defaults to true.
- defer_check_on_battery
- 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.
- 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.
- log_dir
- 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.
- 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 writeable.
- 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 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 filesytem 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).
- 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.
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 filesystem inconsistency
is detected to be overridden.
- preen_ok
- This boolean relation overrides the
default behavior controlling whether this filesystem 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 filesystem
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 filesystem 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
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.
- 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).
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 be used if the number of directories in the filesystem
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.
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).
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.)
[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
- /etc/e2fsck.conf
- The configuration file for e2fsck(8)
.
e2fsck(8)
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