e2fsck.conf(5)
NAME
e2fsck.conf - Configuration file for e2fsck
DESCRIPTION
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), " " (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 [options] STANZA
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 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).
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
filesystem); 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 [problems] STANZA
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 [scratch_files] STANZA
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.
LOGGING
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
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
FILES
/etc/e2fsck.conf
The configuration file for e2fsck(8).
SEE ALSO
e2fsck(8)
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