e2fsck/e2fsck.conf.5.in

   1 .\" -*- nroff -*-
   2 .\" Copyright 2006 by Theodore Ts'o.  All Rights Reserved.
   3 .\" This file may be copied under the terms of the GNU Public License.
   4 .\"
   5 .TH e2fsck.conf 5 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
   6 .SH NAME
   7 e2fsck.conf \- Configuration file for e2fsck
   8 .SH DESCRIPTION
   9 .I e2fsck.conf
  10 is the configuration file for
  11 .BR e2fsck (8).
  12 It controls the default behavior of
  13 .BR e2fsck (8)
  14 while it is checking ext2, ext3, or ext4 filesystems.
  15 .PP
  16 The
  17 .I e2fsck.conf
  18 file uses an INI-style format.  Stanzas, or top-level sections, are
  19 delimited by square braces: [ ].  Within each section, each line
  20 defines a relation, which assigns tags to values, or to a subsection,
  21 which contains further relations or subsections.
  22 .\" Tags can be assigned multiple values
  23 An example of the INI-style format used by this configuration file
  24 follows below:
  25 .P
  26         [section1]
  27 .br
  28                 tag1 = value_a
  29 .br
  30                 tag1 = value_b
  31 .br
  32                 tag2 = value_c
  33 .P
  34         [section 2]
  35 .br
  36                 tag3 = {
  37 .br
  38                         subtag1 = subtag_value_a
  39 .br
  40                         subtag1 = subtag_value_b
  41 .br
  42                         subtag2 = subtag_value_c
  43 .br
  44                 }
  45 .br
  46                 tag1 = value_d
  47 .br
  48                 tag2 = value_e
  49 .br
  50         }
  51 .P
  52 Comments are delimited by a semicolon (';') or a hash ('#') character
  53 at the beginning of the comment, and are terminated by the end of
  54 line character.
  55 .P
  56 Tags and values must be quoted using double quotes if they contain
  57 spaces.  Within a quoted string, the standard backslash interpretations
  58 apply: "\en" (for the newline character),
  59 "\et" (for the tab character), "\eb" (for the backspace character),
  60 and "\e\e" (for the backslash character).
  61 .P
  62 The following stanzas are used in the
  63 .I e2fsck.conf
  64 file.  They will be described in more detail in future sections of this
  65 document.
  66 .TP
  67 .I [options]
  68 This stanza contains general configuration parameters for
  69 .BR e2fsck 's
  70 behavior.
  71 .TP
  72 .I [problems]
  73 This stanza allows the administrator to reconfigure how e2fsck handles
  74 various filesystem inconsistencies.
  75 @TDB_MAN_COMMENT@.TP
  76 @TDB_MAN_COMMENT@.I [scratch_files]
  77 @TDB_MAN_COMMENT@This stanza controls when e2fsck will attempt to use
  78 @TDB_MAN_COMMENT@scratch files to reduce the need for memory.
  79 .SH THE [options] STANZA
  80 The following relations are defined in the
  81 .I [options]
  82 stanza.
  83 .TP
  84 .I allow_cancellation
  85 If this relation is set to a boolean value of true, then if the user
  86 interrupts e2fsck using ^C, and the filesystem is not explicitly flagged
  87 as containing errors, e2fsck will exit with an exit status of 0 instead
  88 of 32.  This setting defaults to false.
  89 .TP
  90 .I accept_time_fudge
  91 Unfortunately, due to Windows' unfortunate design decision
  92 to configure the hardware clock to tick localtime, instead
  93 of the more proper and less error-prone UTC time, many
  94 users end up in the situation where the system clock is
  95 incorrectly set at the time when e2fsck is run.
  96 .IP
  97 Historically this was usually due to some distributions
  98 having buggy init scripts and/or installers that didn't
  99 correctly detect this case and take appropriate
 100 countermeasures.  Unfortunately, this is occasionally
 101 true even today, usually due to a
 102 buggy or misconfigured virtualization manager or the
 103 installer not having access to a network time server
 104 during the installation process.  So by default, we allow
 105 the superblock times to be fudged by up to 24 hours.
 106 This can be disabled by setting
 107 .I accept_time_fudge
 108 to the
 109 boolean value of false.  This setting defaults to true.
 110 .TP
 111 .I broken_system_clock
 112 The
 113 .BR e2fsck (8)
 114 program has some heuristics that assume that the system clock is
 115 correct.  In addition, many system programs make similar assumptions.
 116 For example, the UUID library depends on time not going backwards in
 117 order for it to be able to make its guarantees about issuing universally
 118 unique ID's.  Systems with broken system clocks, are well, broken.
 119 However, broken system clocks, particularly in embedded systems, do
 120 exist.  E2fsck will attempt to use heuristics to determine if the time
 121 can not be trusted; and to skip time-based checks if this is true.  If
 122 this boolean is set to true, then e2fsck will always assume that the
 123 system clock can not be trusted.
 124 .TP
 125 .I buggy_init_scripts
 126 This boolean relation is an alias for
 127 .I accept_time_fudge
 128 for backwards compatibility; it used to
 129 be that the behavior defined by
 130 .I accept_time_fudge
 131 above defaulted to false, and
 132 .I buggy_init_scripts
 133 would enable superblock time field to be wrong by up to 24 hours.  When
 134 we changed the default, we also renamed this boolean relation to
 135 .IR accept_time_fudge.
 136 .TP
 137 .I clear_test_fs_flag
 138 This boolean relation controls whether or not
 139 .BR e2fsck (8)
 140 will offer to clear
 141 the test_fs flag if the ext4 filesystem is available on the system.  It
 142 defaults to true.
 143 .TP
 144 .I defer_check_on_battery
 145 This boolean relation controls whether or not the interval between
 146 filesystem checks (either based on time or number of mounts) should
 147 be doubled if the system is running on battery.  This setting defaults to
 148 true.
 149 .TP
 150 .I indexed_dir_slack_percentage
 151 When
 152 .BR e2fsck (8)
 153 repacks a indexed directory, reserve the specified percentage of
 154 empty space in each leaf nodes so that a few new entries can
 155 be added to the directory without splitting leaf nodes, so that
 156 the average fill ratio of directories can be maintained at a
 157 higher, more efficient level.  This relation defaults to 20
 158 percent.
 159 .TP
 160 .I log_dir
 161 If the
 162 .I log_filename
 163 relation contains a relative pathname, then the log file will be placed
 164 in the directory named by the
 165 .I log_dir
 166 relation.
 167 .TP
 168 .I log_dir_fallback
 169 This relation contains an alternate directory that will be used if the
 170 directory specified by
 171 .I log_dir
 172 is not available or is not writeable.
 173 .TP
 174 .I log_dir_wait
 175 If this boolean relation is true, them if the directories specified by
 176 .I log_dir
 177 or
 178 .I log_dir_fallback
 179 are not available or are not yet writeable, e2fsck will save the output
 180 in a memory buffer, and a child process will periodically test to see if
 181 the log directory has become available after the boot sequence has
 182 mounted the requiste file system for reading/writing.  This implements the
 183 functionality provided by
 184 .BR logsave (8)
 185 for e2fsck log files.
 186 .TP
 187 .I log_filename
 188 This relation specifies the file name where a copy of e2fsck's output
 189 will be written.   If certain problem reports are suppressed using the
 190 .I max_count_problems
 191 relation, (or on a per-problem basis using the
 192 .I max_count
 193 relation), the full set of problem reports will be written to the log
 194 file.  The filename may contain various percent-expressions (%D, %T, %N,
 195 etc.) which will be expanded so that the file name for the log file can
 196 include things like date, time, device name, and other run-time
 197 parameters.  See the
 198 .B LOGGING
 199 section for more details.
 200 .TP
 201 .I max_count_problems
 202 This relation specifies the maximum number of problem reports of a
 203 particular type will be printed to stdout before further problem reports
 204 of that type are squelched.  This can be useful if the console is slow
 205 (i.e., connected to a serial port) and so a large amount of output could
 206 end up delaying the boot process for a long time (potentially hours).
 207 .TP
 208 .I no_optimize_extents
 209 Do not offer to optimize the extent tree by eliminating unnecessary
 210 width or depth.
 211 .TP
 212 .I readahead_mem_pct
 213 Use this percentage of memory to try to read in metadata blocks ahead of the
 214 main e2fsck thread.  This should reduce run times, depending on the speed of
 215 the underlying storage and the amount of free memory.  There is no default, but
 216 see
 217 .B readahead_kb
 218 for more details.
 219 .TP
 220 .I readahead_kb
 221 Use this amount of memory to read in metadata blocks ahead of the main checking
 222 thread.  Setting this value to zero disables readahead entirely.  By default,
 223 this is set the size of two block groups' inode tables (typically 4MiB on a
 224 regular ext4 filesystem); if this amount is more than 1/50th of total physical
 225 memory, readahead is disabled.
 226 .TP
 227 .I report_features
 228 If this boolean relation is true, e2fsck will print the file system
 229 features as part of its verbose reporting (i.e., if the
 230 .B -v
 231 option is specified)
 232 .TP
 233 .I report_time
 234 If this boolean relation is true, e2fsck will run as if the options
 235 .B -tt
 236 are always specified.  This will cause e2fsck to print timing statistics
 237 on a pass by pass basis for full file system checks.
 238 .TP
 239 .I report_verbose
 240 If this boolean relation is true, e2fsck will run as if the option
 241 .B -v
 242 is always specified.  This will cause e2fsck to print some additional
 243 information at the end of each full file system check.
 244 .SH THE [problems] STANZA
 245 Each tag in the
 246 .I [problems]
 247 stanza names a problem code specified with a leading "0x" followed by
 248 six hex digits.
 249 The value of the tag is a subsection where the relations in that
 250 subsection override the default treatment of that particular problem
 251 code.
 252 .P
 253 Note that inappropriate settings in this stanza may cause
 254 .B e2fsck
 255 to behave incorrectly, or even crash.  Most system administrators should
 256 not be making changes to this section without referring to source code.
 257 .P
 258 Within each problem code's subsection, the following tags may be used:
 259 .TP
 260 .I description
 261 This relation allows the message which is printed when this filesystem
 262 inconsistency is detected to be overridden.
 263 .TP
 264 .I preen_ok
 265 This boolean relation overrides the default behavior controlling
 266 whether this filesystem problem should be automatically fixed when
 267 .B e2fsck
 268 is running in preen mode.
 269 .TP
 270 .I max_count
 271 This integer relation overrides the
 272 .I max_count_problems
 273 parameter (set in the options section) for this particular problem.
 274 .TP
 275 .I no_ok
 276 This boolean relation overrides the default behavior determining
 277 whether or not the filesystem will be marked as inconsistent if the user
 278 declines to fix the reported problem.
 279 .TP
 280 .I no_default
 281 This boolean relation overrides whether the default answer for this
 282 problem (or question) should be "no".
 283 .TP
 284 .I preen_nomessage
 285 This boolean relation overrides the default behavior controlling
 286 whether or not the description for this filesystem problem should
 287 be suppressed when
 288 .B e2fsck
 289 is running in preen mode.
 290 .TP
 291 .I no_nomsg
 292 This boolean relation overrides the default behavior controlling
 293 whether or not the description for this filesystem problem should
 294 be suppressed when a problem forced not to be fixed, either because
 295 .B e2fsck
 296 is run with the
 297 .B -n
 298 option or because the
 299 .I force_no
 300 flag has been set for the problem.
 301 .TP
 302 .I force_no
 303 This boolean option, if set to true, forces a problem to never be fixed.
 304 That is, it will be as if the user problem responds 'no' to the question
 305 of 'should this problem be fixed?'.  The
 306 .I force_no
 307 option even overrides the
 308 .B -y
 309 option given on the command-line (just for the specific problem, of course).
 310 .TP
 311 .I not_a_fix
 312 This boolean option, it set to true, marks the problem as
 313 one where if the user gives permission to make the requested change,
 314 it does not mean that the file system had a problem which has since
 315 been fixed.  This is used for requests to optimize the file system's
 316 data structure, such as pruning an extent tree.
 317 @TDB_MAN_COMMENT@.SH THE [scratch_files] STANZA
 318 @TDB_MAN_COMMENT@The following relations are defined in the
 319 @TDB_MAN_COMMENT@.I [scratch_files]
 320 @TDB_MAN_COMMENT@stanza.
 321 @TDB_MAN_COMMENT@.TP
 322 @TDB_MAN_COMMENT@.I directory
 323 @TDB_MAN_COMMENT@If the directory named by this relation exists and is
 324 @TDB_MAN_COMMENT@writeable, then e2fsck will attempt to use this
 325 @TDB_MAN_COMMENT@directory to store scratch files instead of using
 326 @TDB_MAN_COMMENT@in-memory data structures.
 327 @TDB_MAN_COMMENT@.TP
 328 @TDB_MAN_COMMENT@.I numdirs_threshold
 329 @TDB_MAN_COMMENT@If this relation is set, then in-memory data structures
 330 @TDB_MAN_COMMENT@be used if the number of directories in the filesystem
 331 @TDB_MAN_COMMENT@are fewer than amount specified.
 332 @TDB_MAN_COMMENT@.TP
 333 @TDB_MAN_COMMENT@.I dirinfo
 334 @TDB_MAN_COMMENT@This relation controls whether or not the scratch file
 335 @TDB_MAN_COMMENT@directory is used instead of an in-memory data
 336 @TDB_MAN_COMMENT@structure for directory information.  It defaults to
 337 @TDB_MAN_COMMENT@true.
 338 @TDB_MAN_COMMENT@.TP
 339 @TDB_MAN_COMMENT@.I icount
 340 @TDB_MAN_COMMENT@This relation controls whether or not the scratch file
 341 @TDB_MAN_COMMENT@directory is used instead of an in-memory data
 342 @TDB_MAN_COMMENT@structure when tracking inode counts.  It defaults to
 343 @TDB_MAN_COMMENT@true.
 344 .SH LOGGING
 345 E2fsck has the facility to save the information from an e2fsck run in a
 346 directory so that a system administrator can review its output at their
 347 leisure.  This allows information captured during the automatic e2fsck
 348 preen run, as well as a manually started e2fsck run, to be saved for
 349 posterity.  This facility is controlled by the
 350 .IR log_filename ,
 351 .IR log_dir ,
 352 .IR log_dir_fallback ,
 353 and
 354 .I log_dir_wait
 355 relations in the
 356 .I [options]
 357 stanza.
 358 .PP
 359 The filename in
 360 .I log_filename
 361 may contain the following percent-expressions that will be expanded as
 362 follows.
 363 .TP
 364 .B %d
 365 The current day of the month
 366 .TP
 367 .B %D
 368 The current date; this is a equivalent of
 369 .B %Y%m%d
 370 .TP
 371 .B %h
 372 The hostname of the system.
 373 .TP
 374 .B %H
 375 The current hour in 24-hour format (00..23)
 376 .TP
 377 .B %m
 378 The current month as a two-digit number (01..12)
 379 .TP
 380 .B %M
 381 The current minute (00..59)
 382 .TP
 383 .B %N
 384 The name of the block device containing the file system, with any
 385 directory pathname stripped off.
 386 .TP
 387 .B %p
 388 The pid of the e2fsck process
 389 .TP
 390 .B %s
 391 The current time expressed as the number of seconds since 1970-01-01
 392 00:00:00 UTC
 393 .TP
 394 .B %S
 395 The current second (00..59)
 396 .TP
 397 .B %T
 398 The current time; this is equivalent of
 399 .B %H%M%S
 400 .TP
 401 .B %u
 402 The name of the user running e2fsck.
 403 .TP
 404 .B %U
 405 This percent expression does not expand to anything, but it signals that
 406 any following date or time expressions should be expressed in UTC time
 407 instead of the local timzeone.
 408 .TP
 409 .B %y
 410 The last two digits of the current year (00..99)
 411 .TP
 412 .B %Y
 413 The current year (i.e., 2012).
 414 .SH EXAMPLES
 415 The following recipe will prevent e2fsck from aborting during the boot
 416 process when a filesystem contains orphaned files.  (Of course, this is
 417 not always a good idea, since critical files that are needed for the
 418 security of the system could potentially end up in lost+found, and
 419 starting the system without first having a system administrator check
 420 things out may be dangerous.)
 421 .P
 422 .br
 423         [problems]
 424 .br
 425                 0x040002 = {
 426 .br
 427                         preen_ok = true
 428 .br
 429                         description = "@u @i %i.  "
 430 .br
 431                 }
 432 .P
 433 The following recipe will cause an e2fsck logfile to be written to the
 434 directory /var/log/e2fsck, with a filename that contains the device
 435 name, the hostname of the system, the date, and time: e.g.,
 436 "e2fsck-sda3.server.INFO.20120314-112142".  If the directory containing
 437 /var/log is located on the root file system
 438 which is initially mounted read-only, then the output will be saved in
 439 memory and written out once the root file system has been remounted
 440 read/write.   To avoid too much detail from being written to the serial
 441 console (which could potentially slow down the boot sequence), only print
 442 no more than 16 instances of each type of file system corruption.
 443 .P
 444 .br
 445         [options]
 446 .br
 447                 max_count_problems = 16
 448 .br
 449                 log_dir = /var/log/e2fsck
 450 .br
 451                 log_filename = e2fsck-%N.%h.INFO.%D-%T
 452 .br
 453                 log_dir_wait = true
 454 .P
 455 .SH FILES
 456 .TP
 457 .I /etc/e2fsck.conf
 458 The configuration file for
 459 .BR e2fsck (8).
 460 .SH SEE ALSO
 461 .BR e2fsck (8)