Ubuntu Manpage: logrotate ‐ rotates, compresses, and mails system logs

NAME

       logrotate ‐ rotates, compresses, and mails system logs

SYNOPSIS

       logrotate  [--force]  [--debug] [--state file] [--skip-state-lock] [--wait-for-state-lock]
       [--verbose] [--log file] [--mail command] config_file [config_file2 ...]

DESCRIPTION

       logrotate is designed to ease administration of systems that generate large numbers of log
       files.   It  allows  automatic  rotation,  compression, removal, and mailing of log files.
       Each log file may be handled daily, weekly, monthly, or when it grows too large.

       Normally, logrotate is run as a daily cron job.  It will not modify a log more  than  once
       in  one  day unless the criterion for that log is based on the log's size and logrotate is
       being run more than once each day, or unless the -f or --force option is used.

       Any number of config files may be given on the  command  line.   Later  config  files  may
       override  the  options  given in earlier files, so the order in which the logrotate config
       files are listed is important.  Normally, a single config file which  includes  any  other
       config  files  which  are needed should be used.  See below for more information on how to
       use the include directive to accomplish this.  If a directory  is  given  on  the  command
       line, every file in that directory is used as a config file.

       If  no  command  line  arguments  are  given,  logrotate  will print version and copyright
       information, along with a short usage summary.  If any errors occur while  rotating  logs,
       logrotate will exit with non-zero status, although the state file will be updated.

OPTIONS

-f, --force
Tells logrotate to force the rotation, even if it doesn't think this is necessary.
Sometimes this is useful after adding new entries to a logrotate config file, or if
old log files have been removed by hand, as the new files will be created, and
logging will continue correctly.

-d, --debug
Turn on debug mode, which means that no changes are made to the logs and the
logrotate state file is not updated. Only debug messages are printed.

-s, --state statefile
Tells logrotate to use an alternate state file. This is useful if logrotate is
being run as a different user for various sets of log files. To prevent parallel
execution logrotate by default acquires a lock on the state file, if it cannot be
acquired logrotate will exit with value 3. The default state file is
/var/lib/logrotate/status. If /dev/null is given as the state file, then logrotate
will not try to lock or write the state file.

--skip-state-lock
Do not lock the state file, for example if locking is unsupported or prohibited.

--wait-for-state-lock
Wait until lock on the state file is released by another logrotate process. This
option may cause logrotate to wait indefinitely. Use with caution.

-v, --verbose
Turns on verbose mode, for example to display messages during rotation.

-l, --log file
Tells logrotate to log verbose output into the log_file. The verbose output logged
to that file is the same as when running logrotate with -v switch. The log file is
overwritten on every logrotate execution.

-m, --mail command
Tells logrotate which command to use when mailing logs. This command should accept
the following arguments:

1) the subject of the message given with '-s subject'
2) the recipient.

The command must then read a message on standard input and mail it to the
recipient. The default mail command is /usr/bin/mail.

--usage
Prints a short usage message.

-?, --help
Prints help message.

--version
Display version information.

CONFIGURATION FILE

logrotate reads everything about the log files it should be handling from the series of
configuration files specified on the command line. Each configuration file can set global
options (local definitions override global ones, and later definitions override earlier
ones) and specify logfiles to rotate. Global options do not affect preceding include
directives. A simple configuration file looks like this:

# sample logrotate configuration file
compress

/var/log/messages {
rotate 5
weekly
postrotate
/usr/bin/killall -HUP syslogd
endscript
}

"/var/log/httpd/access.log" /var/log/httpd/error.log {
rotate 5
mail recipient@example.org
size 100k
sharedscripts
postrotate
/usr/bin/killall -HUP httpd
endscript
}

/var/log/news/* {
monthly
rotate 2
olddir /var/log/news/old
missingok
sharedscripts
postrotate
kill -HUP $(cat /var/run/inn.pid)
endscript
nocompress
}

~/log/*.log {}

The first few lines set global options; in the example, logs are compressed after they are
rotated. Note that comments may appear anywhere in the config file as long as the first
non-whitespace character on the line is a #.

Values are separated from directives by whitespace and/or an optional =. Numbers must be
specified in a format understood by strtoul(3).

The next section of the config file defines how to handle the log file /var/log/messages.
The log will go through five weekly rotations before being removed. After the log file
has been rotated (but before the old version of the log has been compressed), the command
/usr/bin/killall -HUP syslogd will be executed.

The next section defines the parameters for both /var/log/httpd/access.log and
/var/log/httpd/error.log. Each is rotated whenever it grows over 100 kilobytes in size,
and the old logs files are mailed (uncompressed) to recipient@example.org after going
through 5 rotations, rather than being removed. The sharedscripts means that the
postrotate script will only be run once for this section, not once for each log which is
rotated. Note that log file names may be enclosed in quotes (and that quotes are required
if the name contains spaces). Normal shell quoting rules apply, with ', ", and \
characters supported.

The next section defines the parameters for all of the files in /var/log/news. Each file
is rotated on a monthly basis.

The last section uses tilde expansion to rotate log files in the home directory of the
current user. This is only available, if your glob library supports tilde expansion. GNU
glob does support this.

Please use wildcards with caution. If you specify *, logrotate will rotate all files,
including previously rotated ones. A way around this is to use the olddir directive or a
more exact wildcard (such as *.log).

Please note, by default when using systemd(1), the option ProtectSystem=full is set in the
logrotate.service file. This prevents logrotate from modifying logs in /etc and /usr.

Here is more information on the directives which may be included in a logrotate
configuration file:

CONFIGURATION FILE DIRECTIVES

These directives may be included in a logrotate configuration file:

Rotation
rotate count
Log files are rotated count times before being removed or mailed to the address
specified in a mail directive. If count is 0, old versions are removed rather than
rotated. If count is -1, old logs are not removed at all, except they are affected
by maxage (use with caution, may waste performance and disk space). Default is 0.

olddir directory
Logs are moved into directory for rotation. The directory must be on the same
physical device as the log file being rotated, unless copy, copytruncate or
renamecopy option is used. The directory is assumed to be relative to the
directory holding the log file unless an absolute path name is specified. When
this option is used all old versions of the log end up in directory. This option
may be overridden by the noolddir option.

noolddir
Logs are rotated in the directory they normally reside in (this overrides the
olddir option).

su user group
Rotate log files set under this user and group instead of using default user/group
(usually root). user specifies the user used for rotation and group specifies the
group used for rotation (see the section USER AND GROUP for details). If the
user/group you specify here does not have sufficient privilege to make files with
the ownership you've specified in a create directive, it will cause an error. If
logrotate runs with root privileges, it is recommended to use the su directive to
rotate files in directories that are directly or indirectly in control of non-
privileged users.

Frequency
hourly Log files are rotated every hour. Note that usually logrotate is configured to be
run by cron daily (or by logrotate.timer when using systemd(1)). You have to
change this configuration and run logrotate hourly to be able to really rotate logs
hourly.

daily Log files are rotated every day.

weekly [weekday]
Log files are rotated once each weekday, or if the date is advanced by at least 7
days since the last rotation (while ignoring the exact time). The weekday
interpretation is following: 0 means Sunday, 1 means Monday, ..., 6 means Saturday;
the special value 7 means each 7 days, irrespectively of weekday. Defaults to 0 if
the weekday argument is omitted.

monthly
Log files are rotated the first time logrotate is run in a month (this is normally
on the first day of the month).

yearly Log files are rotated if the current year is not the same as the last rotation.

size size
Log files are rotated only if they grow bigger than size bytes. If size is
followed by k, the size is assumed to be in kilobytes. If M is used, the size is
in megabytes, and if G is used, the size is in gigabytes. So size 100, size 100k,
size 100M and size 100G are all valid. This option is mutually exclusive with the
time interval options, and it causes log files to be rotated without regard for the
last rotation time, if specified after the time criteria (the last specified option
takes the precedence).

File selection
missingok
If the log file is missing, go on to the next one without issuing an error message.
See also nomissingok.

nomissingok
If a log file does not exist, issue an error. This is the default.

ignoreduplicates
Ignore any following matches of a log file.

ifempty
Rotate the log file even if it is empty, overriding the notifempty option (ifempty
is the default).

notifempty
Do not rotate the log if it is empty (this overrides the ifempty option).

minage count
Do not rotate logs which are less than <count> days old.

maxage count
Remove rotated logs older than <count> days. The age is only checked if the
logfile is to be rotated. rotate -1 does not hinder removal. The files are mailed
to the configured address if maillast and mail are configured.

minsize size
Log files are rotated when they grow bigger than size bytes, but not before the
additionally specified time interval (daily, weekly, monthly, or yearly). The
related size option is similar except that it is mutually exclusive with the time
interval options, and it causes log files to be rotated without regard for the last
rotation time, if specified after the time criteria (the last specified option
takes the precedence). When minsize is used, both the size and timestamp of a log
file are considered.

maxsize size
Log files are rotated when they grow bigger than size bytes even before the
additionally specified time interval (daily, weekly, monthly, or yearly). The
related size option is similar except that it is mutually exclusive with the time
interval options, and it causes log files to be rotated without regard for the last
rotation time, if specified after the time criteria (the last specified option
takes the precedence). When maxsize is used, both the size and timestamp of a log
file are considered.

tabooext [+] list
The current taboo extension list is changed (see the include directive for
information on the taboo extensions). If a + precedes the list of extensions, the
current taboo extension list is augmented, otherwise it is replaced. At startup,
the taboo extension list ,v, .bak, .cfsaved, .disabled, .dpkg-bak, .dpkg-del,
.dpkg-dist, .dpkg-new, .dpkg-old, .dpkg-tmp, .new, .old, .orig, .rhn-cfg-tmp-*,
.rpmnew, .rpmorig, .rpmsave, .swp, .ucf-dist, .ucf-new, .ucf-old, ~

taboopat [+] list
The current taboo glob pattern list is changed (see the include directive for
information on the taboo extensions and patterns). If a + precedes the list of
patterns, the current taboo pattern list is augmented, otherwise it is replaced.
At startup, the taboo pattern list is empty.

Files and Folders
create mode owner group, create owner group
Immediately after rotation (before the postrotate script is run) the log file is
created (with the same name as the log file just rotated). mode specifies the mode
for the log file in octal (the same as chmod(2)), owner specifies the user who will
own the log file, and group specifies the group the log file will belong to (see
the section USER AND GROUP for details). Any of the log file attributes may be
omitted, in which case those attributes for the new file will use the same values
as the original log file for the omitted attributes. This option can be disabled
using the nocreate option.

nocreate
New log files are not created (this overrides the create option).

createolddir mode [owner [group]], createolddir [owner [group]]
If the directory specified by olddir directive does not exist, it is created. mode
specifies the mode for the olddir directory in octal (the same as chmod(2)), owner
specifies the user who will own the olddir directory, and group specifies the group
the olddir directory will belong to (see the section USER AND GROUP for details).
If mode is not specified, 0755 is assumed. This option can be disabled using the
nocreateolddir option.

nocreateolddir
olddir directory is not created by logrotate when it does not exist.

copy Make a copy of the log file, but don't change the original at all. This option can
be used, for instance, to make a snapshot of the current log file, or when some
other utility needs to truncate or parse the file. When this option is used, the
create option will have no effect, as the old log file stays in place. The copy
option allows storing rotated log files on the different devices using olddir
directive.

nocopy Do not copy the original log file and leave it in place. (this overrides the copy
option).

copytruncate
Truncate the original log file to zero size in place after creating a copy, instead
of moving the old log file and optionally creating a new one. It can be used when
some program cannot be told to close its logfile and thus might continue writing
(appending) to the previous log file forever. Note that there is a very small time
slice between copying the file and truncating it, so some logging data might be
lost. When this option is used, the create option will have no effect, as the old
log file stays in place. The copytruncate option allows storing rotated log files
on the different devices using olddir directive. The copytruncate option implies
norenamecopy.

nocopytruncate
Do not truncate the original log file in place after creating a copy (this
overrides the copytruncate option).

renamecopy
Log file is renamed to temporary filename in the same directory by adding ".tmp"
extension to it. After that, postrotate script is run and log file is copied from
temporary filename to final filename. In the end, temporary filename is removed.
The renamecopy option allows storing rotated log files on the different devices
using olddir directive. The renamecopy option implies nocopytruncate.

norenamecopy
Do not rename and copy the original log file (this overrides the renamecopy
option).

shred Delete log files using shred -u instead of unlink(). This should ensure that logs
are not readable after their scheduled deletion; this is off by default. See also
noshred.

noshred
Do not use shred when deleting old log files. See also shred.

shredcycles count
Asks GNU shred(1) to overwrite log files count times before deletion. Without this
option, shred's default will be used.

allowhardlink
Rotate files with multiple hard links; this is off by default. The target file
might get emptied, e.g. with shred or copytruncate. Use with caution, especially
when the log files are rotated as root.

noallowhardlink
Do not rotate files with multiple hard links. See also allowhardlink.

Compression
compress
Old versions of log files are compressed with gzip(1) by default. See also
nocompress.

nocompress
Old versions of log files are not compressed. See also compress.

compresscmd
Specifies which command to use to compress log files. The default is gzip(1). See
also compress.

uncompresscmd
Specifies which command to use to uncompress log files. The default is gunzip(1).

compressext
Specifies which extension to use on compressed logfiles, if compression is enabled.
The default follows that of the configured compression command.

compressoptions
Command line options may be passed to the compression program, if one is in use.
The default, for gzip(1), is "-6" (biased towards high compression at the expense
of speed). If you use a different compression command, you may need to change the
compressoptions to match.

delaycompress
Postpone compression of the previous log file to the next rotation cycle. This
only has effect when used in combination with compress. It can be used when some
program cannot be told to close its logfile and thus might continue writing to the
previous log file for some time.

nodelaycompress
Do not postpone compression of the previous log file to the next rotation cycle
(this overrides the delaycompress option).

Filenames
extension ext
Log files with ext extension can keep it after the rotation. If compression is
used, the compression extension (normally .gz) appears after ext. For example you
have a logfile named mylog.foo and want to rotate it to mylog.1.foo.gz instead of
mylog.foo.1.gz.

addextension ext
Log files are given the final extension ext after rotation. If the original file
already ends with ext, the extension is not duplicated, but merely moved to the
end, that is both filename and filenameext would get rotated to filename.1ext. If
compression is used, the compression extension (normally .gz) appears after ext.

start count
This is the number to use as the base for rotation. For example, if you specify 0,
the logs will be created with a .0 extension as they are rotated from the original
log files. If you specify 9, log files will be created with a .9, skipping 0–8.
Files will still be rotated the number of times specified with the rotate
directive.

dateext
Archive old versions of log files adding a date extension like YYYYMMDD instead of
simply adding a number. The extension may be configured using the dateformat and
dateyesterday options.

nodateext
Do not archive old versions of log files with date extension (this overrides the
dateext option).

dateformat format_string
Specify the extension for dateext using the notation similar to strftime(3)
function. Only %Y %m %d %H %M %S %V %s and %z specifiers are allowed. The default
value is -%Y%m%d except hourly, which uses -%Y%m%d%H as default value. Note that
also the character separating log name from the extension is part of the dateformat
string. The system clock must be set past Sep 9th 2001 for %s to work correctly.
Note that the datestamps generated by this format must be lexically sortable (that
is first the year, then the month then the day. For example 2001/12/01 is ok, but
01/12/2001 is not, since 01/11/2002 would sort lower while it is later). This is
because when using the rotate option, logrotate sorts all rotated filenames to find
out which logfiles are older and should be removed.

dateyesterday
Use yesterday's instead of today's date to create the dateext extension, so that
the rotated log file has a date in its name that is the same as the timestamps
within it.

datehourago
Use hour ago instead of current date to create the dateext extension, so that the
rotated log file has a hour in its name that is the same as the timestamps within
it. Useful with rotate hourly.

Mail
mail address
When a log is rotated out of existence, it is mailed to address. If no mail should
be generated by a particular log, the nomail directive may be used.

nomail Do not mail old log files to any address.

mailfirst
When using the mail command, mail the just-rotated file, instead of the about-to-
expire file.

maillast
When using the mail command, mail the about-to-expire file, instead of the just-
rotated file (this is the default).

Additional config files
include file_or_directory
Reads the file given as an argument as if it was included inline where the include
directive appears. If a directory is given, most of the files in that directory
are read in alphabetic order before processing of the including file continues.
The only files which are ignored are files which are not regular files (such as
directories and named pipes) and files whose names end with one of the taboo
extensions or patterns, as specified by the tabooext or taboopat directives,
respectively. The given path may start with ~/ to make it relative to the home
directory of the executing user. For security reasons configuration files must not
be group-writable nor world-writable.

Scripts
sharedscripts
Normally, prerotate and postrotate scripts are run for each log which is rotated
and the absolute path to the log file is passed as first argument to the script.
That means a single script may be run multiple times for log file entries which
match multiple files (such as the /var/log/news/* example). If sharedscripts is
specified, the scripts are only run once, no matter how many logs match the
wildcarded pattern, and whole pattern is passed to them. However, if none of the
logs in the pattern require rotating, the scripts will not be run at all. If the
scripts exit with error (or any log fails to rotate), the remaining actions will
not be executed for any logs. This option overrides the nosharedscripts option.

nosharedscripts
Run prerotate and postrotate scripts for every log file which is rotated (this is
the default, and overrides the sharedscripts option). The absolute path to the log
file is passed as first argument to the script. The absolute path to the final
rotated log file is passed as the second argument to the postrotate script. If the
scripts exit with error, the remaining actions will not be executed for the
affected log only.

firstaction
script
endscript
The script is executed once before all log files that match the wildcarded pattern
are rotated, before the prerotate script is run and only if at least one log will
actually be rotated. These directives may only appear inside a log file
definition. The whole pattern is passed to the script as its first argument. If
the script exits with an error, no further processing is done. See also lastaction
and the SCRIPTS section.

lastaction
script
endscript
The script is executed once after all log files that match the wildcarded pattern
are rotated, after the postrotate script is run and only if at least one log is
rotated. These directives may only appear inside a log file definition. The whole
pattern is passed to the script as its first argument. If the script exits with an
error, just an error message is shown (as this is the last action). See also
firstaction and the SCRIPTS section.

prerotate
script
endscript
The script is executed before the log file and its old logs are rotated and only if
the log will actually be rotated. These directives may only appear inside a log
file definition. Normally, the absolute path to the log file is passed as the
first argument to the script. If sharedscripts is specified, the whole pattern is
passed to the script. See also postrotate and the SCRIPTS section. See
sharedscripts and nosharedscripts for error handling.

postrotate
script
endscript
The script is executed after the log file is rotated and before the log file is
being compressed. These directives may only appear inside a log file definition.
Normally, the absolute path to the log file is passed as the first argument to the
script and the absolute path to the final rotated log file is passed as the second
argument to the script. If sharedscripts is specified, the whole pattern is passed
as the first argument to the script, and the second argument is omitted. See also
prerotate and the SCRIPTS section. See sharedscripts and nosharedscripts for error
handling.

preremove
script
endscript
The script is executed once just before removal of a log file. logrotate will pass
the name of file which is soon to be removed as the first argument to the script.
See also firstaction and the SCRIPTS section.

SCRIPTS

       The lines between the starting keyword (e.g. prerotate) and endscript (both of which  must
       appear  on  lines  by  themselves) are executed (using /bin/sh).  The script inherits some
       traits from the logrotate process, including stderr, stdout, the  current  directory,  the
       environment,  and the umask.  Scripts are run as the invoking user and group, irrespective
       of any su directive.  If the --log flag was specified, file descriptor 3 is the log  file.
       The current working directory is unspecified.

USER AND GROUP

       User and group identifiers are resolved first by trying the textual representation and, in
       case it fails, afterwards by the numeric value.

FILES

       /var/lib/logrotate/status   Default state file.
       /etc/logrotate.conf         Configuration options.

AUTHORS

       Erik Troan, Preston Brown, Jan Kaluza.

       <https://github.com/logrotate/logrotate>