Man page 8 : logrotate

logrotate - rotates, compresses, and mails system logs

logrotate [-dv] [-f|--force] [-s|\fB--state file] config_file ..

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.

• -d
      Turns on debug mode and implies -v. In debug mode, no changes will be made to the logs or to the logrotate state file.
• -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.
• -m, --mail <command>
      Tells logrotate which command to use when mailing logs. This command should accept two arguments: 1) the subject of the message, and 2) the recipient. The command must then read a message on standard input and mail it to the recipient. The default mail command is \fB/usr/bin/mail -s\fR.
• -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. The default state file is /var/lib/logrotate/status.
• --usage
      Prints a short usage message.
• -v, --verbose
      Turns on verbose mode, ie. display messages during rotation.

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. A simple configuration file looks like this:

+8n
# 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 www@my.org
    size 100k
    sharedscripts
    postrotate
        /usr/bin/killall -HUP httpd
    endscript
}
/var/log/news/* {
    monthly
    rotate 2
    olddir /var/log/news/old
    missingok
    postrotate
        kill -HUP `cat /var/run/inn.pid`
    endscript
    nocompress
}

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 #. 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 /sbin/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 100k in size, and the old logs files are mailed (uncompressed) to after going through 5 rotations, rather than being removed. The sharedscripts means that the postrotate script will only be run once (after the old logs have been compressed), 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 last section defines the parameters for all of the files in /var/log/news. Each file is rotated on a monthly basis. This is considered a single rotation directive and if errors occur for more than one file, the log files are not compressed. 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). If the directory /var/log/news does not exist, this will cause logrotate to report an error. This error cannot be stopped with the missingok directive. Here is more information on the directives which may be included in a logrotate configuration file:

• compress
      Old versions of log files are compressed with gzip(1) by default. See also nocompress.
• 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 "-9" (maximum compression).
• 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.
• 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.
• \fBcreate mode 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 name who will own the log file, and group specifies the group the log file will belong to. 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.
• daily
      Log files are rotated every day.
• dateext
      Archive old versions of log files adding a daily extension like YYYYMMDD instead of simply adding a number. The extension may be configured using the dateformat option.
• dateformat format_string
      Specify the extension for dateext using the notation similar to strftime(3) function. Only %Y %m %d and %s specifiers are allowed. The default value is -%Y%m%d. 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.
• 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.
• \fBextension 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.
• ifempty
      Rotate the log file even if it is empty, overriding the notifempty option (ifempty is the default).
• \fBinclude 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, as specified by the tabooext directive. The include directive may not appear inside a log file definition.
• \fBmail 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.
• 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).
• maxage count
      Remove rotated logs older than <count> days. The age is only checked if the logfile is to be rotated. 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. When minsize is used, both the size and timestamp of a log file are considered.
• missingok
      If the log file is missing, go on to the next one without issuing an error message. See also nomissingok.
• monthly
      Log files are rotated the first time logrotate is run in a month (this is normally on the first day of the month).
• nocompress
      Old versions of log files are not compressed. See also compress.
• nocopy
      Do not copy the original log file and leave it in place. (this overrides the copy option).
• nocopytruncate
      Do not truncate the original log file in place after creating a copy (this overrides the copytruncate option).
• nocreate
      New log files are not created (this overrides the create option).
• nodelaycompress
      Do not postpone compression of the previous log file to the next rotation cycle (this overrides the delaycompress option).
• nodateext
      Do not archive old versions of log files with date extension (this overrides the dateext option).
• nomail
      Do not mail old log files to any address.
• nomissingok
      If a log file does not exist, issue an error. This is the default.
• noolddir
      Logs are rotated in the directory they normally reside in (this overrides the olddir option).
• nosharedscripts
      Run prerotate and postrotate scripts for every log file which is rotated (this is the default, and overrides the sharedscripts option). If the scripts exit with error, the remaining actions will not be executed for the affected log only.
• noshred
      Do not use shred when deleting old log files. See also shred.
• notifempty
      Do not rotate the log if it is empty (this overrides the ifempty option).
• \fBolddir directory
      Logs are moved into directory for rotation. The directory must be on the same physical device as the log file being rotated, and 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.
• postrotate/endscript
      The lines between postrotate and endscript (both of which must appear on lines by themselves) are executed after the log file is rotated. These directives may only appear inside a log file definition. See also prerotate. See sharedscripts and nosharedscripts for error handling.
• prerotate/endscript
      The lines between prerotate and endscript (both of which must appear on lines by themselves) are executed before the log file is rotated and only if the log will actually be rotated. These directives may only appear inside a log file definition. See also postrotate. See sharedscripts and nosharedscripts for error handling.
• firstaction/endscript
      The lines between firstaction and endscript (both of which must appear on lines by themselves) are executed once before all log files that match the wildcarded pattern are rotated, before 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. If the script exits with error, no further processing is done. See also lastaction.
• lastaction/endscript
      The lines between lastaction and endscript (both of which must appear on lines by themselves) are executed once after all log files that match the wildcarded pattern are rotated, after postrotate script is run and only if at least one log is rotated. These directives may only appear inside a log file definition. If the script exits with error, just an error message is shown (as this is the last action). See also firstaction.
• \fBrotate 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.
• \fBsize size
      Log files are rotated when they grow bigger than size bytes. If size is followed by k, the size is assumed to be in kilobytes. If the 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.
• sharedscripts
      Normally, prerotate and postrotate scripts are run for each log which is rotated, meaning that a single script may be run multiple times for log file entries which match multiple files (such as the /var/log/news/* example). If sharedscript is specified, the scripts are only run once, no matter how many logs match the wildcarded pattern. 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, the remaining actions will not be executed for any logs. This option overrides the nosharedscripts option and implies create 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.
• shredcycles count
      Asks GNU shred(1) to overwite log files count times before deletion. Without this option, shred's default will be used.
• \fBstart 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.
• 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 contains .rpmorig, .rpmsave, ,v, .swp, .rpmnew, ~, .cfsaved, .rhn-cfg-tmp-*, .dpkg-dist, .dpkg-old, .dpkg-new, .disabled.
• weekly
      Log files are rotated if the current weekday is less than the weekday of the last rotation or if more than a week has passed since the last rotation. This is normally the same as rotating logs on the first day of the week, but if logrotate is not being run every night a log rotation will happen at the first valid opportunity.
• yearly
      Log files are rotated if the current year is not the same as the last rotation.

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

R gzip (1)

The killall(1) program in Debian is found in the psmisc package.