1e2fsck.conf(5)                File Formats Manual               e2fsck.conf(5)
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NAME

6       e2fsck.conf - Configuration file for e2fsck
7

DESCRIPTION

9       e2fsck.conf  is  the configuration file for e2fsck(8).  It controls the
10       default behavior of e2fsck(8) while it is checking ext2, ext3, or  ext4
11       filesystems.
12
13       The  e2fsck.conf  file uses an INI-style format.  Stanzas, or top-level
14       sections, are delimited by square braces: [ ].   Within  each  section,
15       each  line  defines  a  relation, which assigns tags to values, or to a
16       subsection, which contains further relations or subsections.  An  exam‐
17       ple  of  the  INI-style  format used by this configuration file follows
18       below:
19
20            [section1]
21                 tag1 = value_a
22                 tag1 = value_b
23                 tag2 = value_c
24
25            [section 2]
26                 tag3 = {
27                      subtag1 = subtag_value_a
28                      subtag1 = subtag_value_b
29                      subtag2 = subtag_value_c
30                 }
31                 tag1 = value_d
32                 tag2 = value_e
33            }
34
35       Comments are delimited by a semicolon (';') or a hash  ('#')  character
36       at  the beginning of the comment, and are terminated by the end of line
37       character.
38
39       Tags and values must be quoted using double quotes if they contain spa‐
40       ces.   Within  a  quoted string, the standard backslash interpretations
41       apply: "\n" (for the newline character), "\t" (for the tab  character),
42       "\b" (for the backspace character), and "\\" (for the backslash charac‐
43       ter).
44
45       The following stanzas are used in the e2fsck.conf file.  They  will  be
46       described in more detail in future sections of this document.
47
48       [options]
49              This   stanza  contains  general  configuration  parameters  for
50              e2fsck's behavior.
51
52       [defaults]
53              Contains relations which define the default parameters  used  by
54              e2fsck(8).  In general, these defaults may be overridden by com‐
55              mand-line options provided by the user.
56
57       [problems]
58              This stanza allows the administrator to reconfigure  how  e2fsck
59              handles various filesystem inconsistencies.
60
61       [scratch_files]
62              This  stanza  controls  when  e2fsck will attempt to use scratch
63              files to reduce the need for memory.
64

THE [options] STANZA

66       The following relations are defined in the [options] stanza.
67
68       allow_cancellation
69              If this relation is set to a boolean value of true, then if  the
70              user  interrupts  e2fsck  using  ^C,  and  the filesystem is not
71              explicitly flagged as containing errors, e2fsck will  exit  with
72              an  exit  status  of  0 instead of 32.  This setting defaults to
73              false.
74
75       accept_time_fudge
76              Unfortunately, due to Windows' unfortunate  design  decision  to
77              configure  the  hardware clock to tick localtime, instead of the
78              more proper and less error-prone UTC time, many users end up  in
79              the  situation  where the system clock is incorrectly set at the
80              time when e2fsck is run.
81
82              Historically this was usually due to some  distributions  having
83              buggy  init  scripts  and/or  installers  that  didn't correctly
84              detect this case and take appropriate countermeasures.  Unfortu‐
85              nately,  this  is occasionally true even today, usually due to a
86              buggy or misconfigured virtualization manager or  the  installer
87              not  having access to a network time server during the installa‐
88              tion process.  So by default, we allow the superblock  times  to
89              be  fudged  by  up to 24 hours.  This can be disabled by setting
90              accept_time_fudge to the boolean value of false.   This  setting
91              defaults to true.
92
93       broken_system_clock
94              The  e2fsck(8)  program has some heuristics that assume that the
95              system clock is correct.  In addition, many system programs make
96              similar  assumptions.   For example, the UUID library depends on
97              time not going backwards in order for it to be able to make  its
98              guarantees  about issuing universally unique ID's.  Systems with
99              broken system clocks, are well, broken.  However, broken  system
100              clocks, particularly in embedded systems, do exist.  E2fsck will
101              attempt to use heuristics to determine if the time  can  not  be
102              trusted; and to skip time-based checks if this is true.  If this
103              boolean is set to true, then e2fsck will always assume that  the
104              system clock can not be trusted.
105
106       buggy_init_scripts
107              This  boolean  relation  is  an  alias for accept_time_fudge for
108              backwards compatibility; it used to be that the behavior defined
109              by    accept_time_fudge    above   defaulted   to   false,   and
110              buggy_init_scripts would enable  superblock  time  field  to  be
111              wrong  by  up to 24 hours.  When we changed the default, we also
112              renamed this boolean relation to accept_time_fudge.
113
114       clear_test_fs_flag
115              This boolean relation controls whether  or  not  e2fsck(8)  will
116              offer to clear the test_fs flag if the ext4 filesystem is avail‐
117              able on the system.  It defaults to true.
118
119       defer_check_on_battery
120              This boolean relation  controls  whether  or  not  the  interval
121              between  filesystem  checks  (either  based on time or number of
122              mounts) should be doubled if the system is running  on  battery.
123              This setting defaults to true.
124
125       indexed_dir_slack_percentage
126              When  e2fsck(8)  repacks a indexed directory, reserve the speci‐
127              fied percentage of empty space in each leaf nodes so that a  few
128              new entries can be added to the directory without splitting leaf
129              nodes, so that the average fill  ratio  of  directories  can  be
130              maintained  at  a  higher,  more efficient level.  This relation
131              defaults to 20 percent.
132
133       inode_count_fullmap
134              If this boolean relation is true, trade  off  using  memory  for
135              speed  when  checking a file system with a large number of hard-
136              linked files.  The amount of memory required is proportional  to
137              the  number  of  inodes in the file system.  For large file sys‐
138              tems, this can be gigabytes of memory.  (For example a 40TB file
139              system with 2.8 billion inodes will consume an additional 5.7 GB
140              memory if this optimization is enabled.)  This setting  defaults
141              to false.
142
143       log_dir
144              If the log_filename or problem_log_filename relations contains a
145              relative pathname, then the log  file  will  be  placed  in  the
146              directory named by the log_dir relation.
147
148       log_dir_fallback
149              This  relation contains an alternate directory that will be used
150              if the directory specified by log_dir is not available or is not
151              writable.
152
153       log_dir_wait
154              If this boolean relation is true, them if the directories speci‐
155              fied by log_dir or log_dir_fallback are not available or are not
156              yet  writable,  e2fsck  will save the output in a memory buffer,
157              and a child process will periodically test to  see  if  the  log
158              directory  has  become  available  after  the  boot sequence has
159              mounted the requested file  system  for  reading/writing.   This
160              implements  the  functionality provided by logsave(8) for e2fsck
161              log files.
162
163       log_filename
164              This relation specifies the file name where a copy  of  e2fsck's
165              output  will  be  written.   If certain problem reports are sup‐
166              pressed using the max_count_problems relation,  (or  on  a  per-
167              problem  basis  using  the  max_count relation), the full set of
168              problem reports will be written to the log file.   The  filename
169              may contain various percent-expressions (%D, %T, %N, etc.) which
170              will be expanded so that the file name  for  the  log  file  can
171              include  things like date, time, device name, and other run-time
172              parameters.  See the LOGGING section for more details.
173
174       max_count_problems
175              This relation specifies the maximum number of problem reports of
176              a particular type will be printed to stdout before further prob‐
177              lem reports of that type are squelched.  This can be  useful  if
178              the  console is slow (i.e., connected to a serial port) and so a
179              large amount of output could end up delaying  the  boot  process
180              for a long time (potentially hours).
181
182       no_optimize_extents
183              If  this  boolean relation is true, do not offer to optimize the
184              extent tree by reducing the tree's width or depth.  This setting
185              defaults to false.
186
187       problem_log_filename
188              This  relation  specifies  the  file name where a log of problem
189              codes found by e2fsck be written.  The filename may contain var‐
190              ious  percent-expressions  (%D,  %T,  %N,  etc.)  which  will be
191              expanded so that the file name for  the  log  file  can  include
192              things  like date, time, device name, and other run-time parame‐
193              ters.  See the LOGGING section for more details.
194
195       readahead_mem_pct
196              Use this percentage of memory to try to read in metadata  blocks
197              ahead  of the main e2fsck thread.  This should reduce run times,
198              depending on the speed of the underlying storage and the  amount
199              of  free  memory.  There is no default, but see readahead_kb for
200              more details.
201
202       readahead_kb
203              Use this amount of memory to read in metadata  blocks  ahead  of
204              the  main  checking thread.  Setting this value to zero disables
205              readahead entirely.  By default, this is set  the  size  of  two
206              block  groups'  inode  tables  (typically 4MiB on a regular ext4
207              filesystem); if this amount is more than 1/50th of total  physi‐
208              cal memory, readahead is disabled.
209
210       report_features
211              If  this  boolean  relation  is true, e2fsck will print the file
212              system features as part of its verbose reporting (i.e.,  if  the
213              -v option is specified)
214
215       report_time
216              If  this  boolean  relation  is  true, e2fsck will run as if the
217              options -tt are always specified.  This  will  cause  e2fsck  to
218              print  timing  statistics  on a pass by pass basis for full file
219              system checks.
220
221       report_verbose
222              If this boolean relation is true, e2fsck  will  run  as  if  the
223              option  -v is always specified.  This will cause e2fsck to print
224              some additional information at the end of each full file  system
225              check.
226

THE [defaults] STANZA

228       The following relations are defined in the [defaults] stanza.
229
230       undo_dir
231              This relation specifies the directory where the undo file should
232              be stored.  It can  be  overridden  via  the  E2FSPROGS_UNDO_DIR
233              environment  variable.   If the directory location is set to the
234              value none, e2fsck will not create an undo file.
235

THE [problems] STANZA

237       Each tag in the [problems] stanza names a problem code specified with a
238       leading  "0x"  followed  by  six hex digits.  The value of the tag is a
239       subsection where the relations in that subsection override the  default
240       treatment of that particular problem code.
241
242       Note  that  inappropriate  settings  in this stanza may cause e2fsck to
243       behave incorrectly, or even crash.  Most system  administrators  should
244       not be making changes to this section without referring to source code.
245
246       Within each problem code's subsection, the following tags may be used:
247
248       description
249              This  relation  allows  the  message  which is printed when this
250              filesystem inconsistency is detected to be overridden.
251
252       preen_ok
253              This boolean relation overrides the default behavior controlling
254              whether  this  filesystem  problem should be automatically fixed
255              when e2fsck is running in preen mode.
256
257       max_count
258              This integer relation overrides the max_count_problems parameter
259              (set in the options section) for this particular problem.
260
261       no_ok  This boolean relation overrides the default behavior determining
262              whether or not the filesystem will be marked as inconsistent  if
263              the user declines to fix the reported problem.
264
265       no_default
266              This  boolean  relation overrides whether the default answer for
267              this problem (or question) should be "no".
268
269       preen_nomessage
270              This boolean relation overrides the default behavior controlling
271              whether  or  not  the  description  for  this filesystem problem
272              should be suppressed when e2fsck is running in preen mode.
273
274       no_nomsg
275              This boolean relation overrides the default behavior controlling
276              whether  or  not  the  description  for  this filesystem problem
277              should be suppressed when a problem  forced  not  to  be  fixed,
278              either  because  e2fsck is run with the -n option or because the
279              force_no flag has been set for the problem.
280
281       force_no
282              This boolean option, if set to true, forces a problem  to  never
283              be  fixed.   That is, it will be as if the user problem responds
284              'no' to the question of 'should this problem  be  fixed?'.   The
285              force_no  option  even overrides the -y option given on the com‐
286              mand-line (just for the specific problem, of course).
287
288       not_a_fix
289              This boolean option, it set to true, marks the  problem  as  one
290              where if the user gives permission to make the requested change,
291              it does not mean that the file system had a  problem  which  has
292              since  been  fixed.   This  is used for requests to optimize the
293              file system's data structure, such as pruning an extent tree.
294

THE [scratch_files] STANZA

296       The following relations are defined in the [scratch_files] stanza.
297
298       directory
299              If the directory named by this relation exists and is writeable,
300              then  e2fsck will attempt to use this directory to store scratch
301              files instead of using in-memory data structures.
302
303       numdirs_threshold
304              If this relation is set, then in-memory data structures will  be
305              used  if  the  number of directories in the filesystem are fewer
306              than amount specified.
307
308       dirinfo
309              This relation controls whether or not the scratch file directory
310              is  used  instead  of  an in-memory data structure for directory
311              information.  It defaults to true.
312
313       icount This relation controls whether or not the scratch file directory
314              is  used  instead  of  an in-memory data structure when tracking
315              inode counts.  It defaults to true.
316

LOGGING

318       E2fsck has the facility to save the information from an e2fsck run in a
319       directory so that a system administrator can review its output at their
320       leisure.  This allows information captured during the automatic  e2fsck
321       preen  run,  as  well as a manually started e2fsck run, to be saved for
322       posterity.  This facility is controlled by the  log_filename,  log_dir,
323       log_dir_fallback, and log_dir_wait relations in the [options] stanza.
324
325       The  filename in log_filename may contain the following percent-expres‐
326       sions that will be expanded as follows.
327
328       %d     The current day of the month
329
330       %D     The current date; this is a equivalent of %Y%m%d
331
332       %h     The hostname of the system.
333
334       %H     The current hour in 24-hour format (00..23)
335
336       %m     The current month as a two-digit number (01..12)
337
338       %M     The current minute (00..59)
339
340       %N     The name of the block device containing the  file  system,  with
341              any directory pathname stripped off.
342
343       %p     The pid of the e2fsck process
344
345       %s     The  current  time  expressed  as  the  number  of seconds since
346              1970-01-01 00:00:00 UTC
347
348       %S     The current second (00..59)
349
350       %T     The current time; this is equivalent of %H%M%S
351
352       %u     The name of the user running e2fsck.
353
354       %U     This percent expression does not expand to anything, but it sig‐
355              nals  that  any  following  date  or  time expressions should be
356              expressed in UTC time instead of the local timezone.
357
358       %y     The last two digits of the current year (00..99)
359
360       %Y     The current year (i.e., 2012).
361

EXAMPLES

363       The following recipe will prevent e2fsck from aborting during the  boot
364       process when a filesystem contains orphaned files.  (Of course, this is
365       not always a good idea, since critical files that are  needed  for  the
366       security  of  the  system  could  potentially end up in lost+found, and
367       starting the system without first having a system  administrator  check
368       things out may be dangerous.)
369
370            [problems]
371                 0x040002 = {
372                      preen_ok = true
373                      description = "@u @i %i.  "
374                 }
375
376       The  following recipe will cause an e2fsck logfile to be written to the
377       directory /var/log/e2fsck, with a filename  that  contains  the  device
378       name,  the  hostname  of the system, the date, and time: e.g., "e2fsck-
379       sda3.server.INFO.20120314-112142".    If   the   directory   containing
380       /var/log  is located on the root file system which is initially mounted
381       read-only, then the output will be saved in memory and written out once
382       the root file system has been remounted read/write.   To avoid too much
383       detail from being written to the serial  console  (which  could  poten‐
384       tially  slow  down  the  boot  sequence),  only  print  no more than 16
385       instances of each type of file system corruption.
386
387            [options]
388                 max_count_problems = 16
389                 log_dir = /var/log/e2fsck
390                 log_filename = e2fsck-%N.%h.INFO.%D-%T
391                 log_dir_wait = true
392

FILES

394       /etc/e2fsck.conf
395              The configuration file for e2fsck(8).
396

SEE ALSO

398       e2fsck(8)
399
400
401
402E2fsprogs version 1.45.6          March 2020                    e2fsck.conf(5)
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