logrotate是个强大的系统软件，它对日志文件（只要文件名固定的）有着一套完整的操作模式，譬如：转储、邮件和压缩等等；但是它也有那么点瑕疵：就是转储的时候，文件大小经常不是预期的，譬如，设置成size 1024，那么转储的时候文件大小可能已经上兆了。原因很简单，因为logrotate是个cron任务，它只能每天（最小轮询单位）轮询一次，至于在这一天内文件大小超过1024，它也无能为力。不管怎么说，logrotate是个非常实用的工具，只要对log临时需要（测试）或要求不高，都可以采用。以下是我对logrotate的理解和整理。

logrotate

LOGROTATE(8)             System Administrator’s Manual            LOGROTATE(8)

NAME

       logrotate - rotates, compresses, and mails system logs

SYNOPSIS

       logrotate [-dv] [-f|--force] [-s|--state file] config_file+

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  multiple  times  in  one  day unless the criterium for that log is       based on the log’s size and logrotate is being run multiple times  each       day, or unless the -f or -force option is used.       Any number of config files may be given on the command line. Later con-       fig files may override the options given in earlier files, so the order       in  which  the logrotate config files are listed in is important.  Nor-       mally, 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.

描述：

       为了简化对产生大量日志文件的各种系统的管理，logrotate从而被设计出来。它可以       自动转储、压缩、删除和邮件这些日志。每个日志文件可以在每天，每星期，每月或太       大了的时候被处理。
       通常，logrotate是一个每天执行一次的cron任务。除非被操作的日志文件是以大小处理       的，并且在一天内logrotate被执行多次，或是使用了选项-f或-force，每天logrotate       不会多次修改一个文件。       命令行可以包含任意数量的配置文件。后面的配置文件可能会覆盖前面的配置文件给出的       选项，所以logrotate列出的配置文件顺序是很重要的。通常，如果需要包含其它配置文       件信息，那么应该用一个单一的配置文件。根据下面更多的信息，通过使用include导向       来完成这个。假如命令行上给出的是个目录，那么在这个目录下的文件都被看作是一个配       置文件。       如果命令行不包含任意选项，那么logrotate会打印出它的版本和版权信息，以及一段短       小的用法摘要。

OPTIONS

       -v     Turn on verbose mode.       -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 logrotate, or if old log files have been  removed  by              hand,  as  the  new files will be created, and logging will con-              tinue correctly.       -m, --mail               Tells logrotate which command to use  when  mailing  logs.  This              command  should accept two arguments: 1) the subject of the mes-              sage, 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 /bin/mail -s.       -s, --state               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/sta-              tus.       --usage              Prints a short usage message.

选项：

       -v     打开冗长模式。       -d     打开调试模式，并且隐式打开冗长模式-v。在调试模式下，日志文件和log-            rotate状态文件不会有变化。        -f, --force            告诉logrotate强制轮调，即使它不认为这是必要的。有时这是很有用的，              譬如logrotate增加了新的入口；又如假设旧的日志文件被手动删除了，这              样新的日志文件需要创建出来，保证正常写日志。       -m, --mail             告诉logrotate当邮件日志时调用command。这个command需要包含2个参数：              1) 消息的主题，和 2) 接收者。这个command必须从标准输入上读出消息，然              后发邮件给接收者。默认发邮件命令是/bin/mail -s。        -s, --state             告诉logrotate使用备用的状态文件。当另一个用户正在用logrotate管理大              量的日志文件时，这是非常有用的。默认的状态文件是/var/lib/logrotate            /status。       --usage            打印简要的用法信息。

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 over-       ride global ones, and later  definitions  override  earlier  ones)  and       specify  a  logfile  to  rotate. A simple configuration file looks like       this:       # sample logrotate configuration file       compress       /var/log/messages {           rotate 5           weekly           postrotate                                     /sbin/killall -HUP syslogd           endscript       }       "/var/log/httpd/access.log" /var/log/httpd/error.log {           rotate 5           mail www@my.org           size=100k           sharedscripts           postrotate                                     /sbin/killall -HUP httpd           endscript       }       /var/log/news/news.crit {           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  com-       pressed 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 files defined 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.    They   are       rotated whenever is grows over 100k is size, and the old logs files are       mailed (uncompressed) to www@my.org after going  through  5  rotations,       rather  then 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 the double quotes       around the first filename at  the  beginning  of  this  section  allows       logrotate  to rotate logs with spaces in the name. 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 con-       sidered a single rotation directive and if errors occur for  more  then       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).       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 by default.              See also nocompress.       compresscmd              Specifies which command to  use  to  compress  log  files.   The              default is gzip.  See also compress.       uncompresscmd              Specifies  which  command  to  use to uncompress log files.  The              default is gunzip.       compressext              Specifies which extension to use on compressed logfiles, if com-              pression 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, is "-9" (maximum com-              pression).       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 pare 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 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 can not 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  log-              ging  data  might be lost.  When this option is used, the create              option will have no effect, as the old log file stays in  place.       create 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.       delaycompress              Postpone  compression of the previous log file to the next rota-              tion cycle.  This has only effect when used in combination  with              compress.   It  can be used when some program can not be told to              close its logfile and thus might continue writing to the  previ-              ous log file for some time.       extension ext              Log  files  are given the final extension ext after rotation. If              compression is used, the compression  extension  (normally  .gz)              appears after ext.       ifempty              Rotate  the  log  file  even  if  it  is  empty,  overiding  the              notifempty option (ifempty is the default).       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, as specified by  the  tabooext              directive.  The include directive may not appear inside of a log              file definition.       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.       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).       missingok              If the log file is missing, go on to the next one without  issu-              ing 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 with gzip. 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).       nomail Don’t 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 same directory the log normally  resides              in (this overrides the olddir option).       nosharedscripts              Run  prerotate  and postrotate scripts for every script which is              rotated (this is the default, and  overrides  the  sharedscripts              option).       notifempty              Do not rotate the log if it is empty (this overrides the ifempty              option).       olddir 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 overriden 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 of a log              file definition.  See prerotate as well.       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 of a log file definition.  See              postrotate as well.       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 pre-              rotate  script is run and only if at least one log will actually              be rotated. These directives may only appear  inside  of  a  log              file definition. See lastaction as well.       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 of a log file              definition. See lastaction as well.       rotate count              Log files are rotated   times  before  being  removed  or              mailed to the address specified in a mail directive. If count is              0, old versions are removed rather then rotated.       size size              Log files are rotated when they grow bigger then size bytes.  If              size  is  followed by M, the size if assumed to be in megabytes.              If the k is used, the size is in kilobytes. So  size  100,  size              100k, and size 100M are all valid.       sharedscripts              Normally,  prescript and postscript scripts are run for each log              which is rotated, meaning that a single script may be run multi-              ple  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. This              option overrides the nosharedscripts option and  implies  create              option.       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              count directive.       tabooext [+] list              The current taboo extension list is  changed  (see  the  include              directive  for information on the taboo extensions). If a + pre-              cedes 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,              and ~.       weekly Log  files  are  rotated if the current weekday is less then the              weekday of the last rotation or if more then a week  has  passed              since  the  last rotation. This is normally the same as rotating              logs on the first day of the week, but it works better if logro-              tate is not run every night.

FILES

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

SEE ALSO

       gzip(1)

AUTHORS

       Erik Troan <ewt@redhat.com>       Preston Brown <pbrown@redhat.com>4th Berkeley Distribution       Wed Nov 5 2002                    LOGROTATE(8)

以上是linux man手册上的logrotate。

系统管理员可以使用logrotate 程序用来管理系统中的最新的事件。logrotate 还可以用来备份日志文件，本篇将通过以下几部分来介绍

日志文件的管理：

1、logrotate 配置

2、缺省配置 logrotate

3、使用include 选项读取其他配置文件

4、使用include 选项覆盖缺省配置

5、为指定的文件配置转储参数

一、logrotate 配置

logrotate 程序是一个日志文件管理工具。用来把旧的日志文件删除，并创建新的日志文件，我们把它叫做“转储”。我们可以根据日志文件的大小，也可以根据其天数来转储，这个过程一般通过 cron 程序来执行。

logrotate 程序还可以用于压缩日志文件，以及发送日志到指定的E-mail 。

logrotate 的配置文件是 /etc/logrotate.conf。主要参数如下表：

参数 功能

compress 通过gzip 压缩转储以后的日志

nocompress 不需要压缩时，用这个参数

copytruncate 用于还在打开中的日志文件，把当前日志备份并截断

nocopytruncate 备份日志文件但是不截断

create mode owner group 转储文件，使用指定的文件模式创建新的日志文件

nocreate 不建立新的日志文件

delaycompress 和 compress 一起使用时，转储的日志文件到下一次转储时才压缩

nodelaycompress 覆盖 delaycompress 选项，转储同时压缩。

errors address 专储时的错误信息发送到指定的Email 地址

ifempty 即使是空文件也转储，这个是 logrotate 的缺省选项。

notifempty 如果是空文件的话，不转储

mail address 把转储的日志文件发送到指定的E-mail 地址

nomail 转储时不发送日志文件

olddir directory 转储后的日志文件放入指定的目录，必须和当前日志文件在同一个文件系统

noolddir 转储后的日志文件和当前日志文件放在同一个目录下

prerotate/endscript 在转储以前需要执行的命令可以放入这个对，这两个关键字必须单独成行

postrotate/endscript 在转储以后需要执行的命令可以放入这个对，这两个关键字必须单独成行

daily 指定转储周期为每天

weekly 指定转储周期为每周

monthly 指定转储周期为每月

rotate count 指定日志文件删除之前转储的次数，0 指没有备份，5 指保留5 个备份

tabootext [+] list 让logrotate 不转储指定扩展名的文件，缺省的扩展名是：.rpm-orig, .rpmsave, v, 和 ~

size size 当日志文件到达指定的大小时才转储，Size 可以指定 bytes (缺省)以及KB (sizek)或者MB (sizem).

二、缺省配置 logrotate

logrotate 缺省的配置募??/etc/logrotate.conf。

Red Hat Linux 缺省安装的文件内容是：

# see "man logrotate" for details

# rotate log files weekly

weekly

# keep 4 weeks worth of backlogs

rotate 4

# send errors to root

errors root

# create new (empty) log files after rotating old ones

create

# uncomment this if you want your log files compressed

#compress

1

# RPM packages drop log rotation information into this directory

include /etc/logrotate.d

# no packages own lastlog or wtmp --we'll rotate them here

/var/log/wtmp {

monthly

create 0664 root utmp

rotate 1

}

/var/log/lastlog {

monthly

rotate 1

}

# system-specific logs may be configured here

缺省的配置一般放在logrotate.conf 文件的最开始处，影响整个系统。在本例中就是前面12行。

第三行weekly 指定所有的日志文件每周转储一次。

第五行 rotate 4 指定转储文件的保留 4份。

第七行 errors root 指定错误信息发送给root。

第九行create 指定 logrotate 自动建立新的日志文件，新的日志文件具有和

原来的文件一样的权限。

第11行 #compress 指定不压缩转储文件，如果需要压缩，去掉注释就可以了。

三、使用include 选项读取其他配置文件

include 选项允许系统管理员把分散到几个文件的转储信息，集中到一个

主要的配置文件。当 logrotate 从logrotate.conf 读到include 选项时，会从指定文件读入配置信息，就好像他们已经在/etc/logrotate.conf 中一样。

第13行 include /etc/logrotate.d 告诉 logrotate 读入存放在/etc/logrotate.d 目录中的日志转储参数，当系统中安装了RPM 软件包时，使用include 选项十分有用。RPM 软件包的日志转储参数一般存放在/etc/logrotate.d 目录。

include 选项十分重要，一些应用把日志转储参数存放在 /etc/logrotate.d 。

典型的应用有：apache, linuxconf, samba, cron 以及syslog。

这样，系统管理员只要管理一个 /etc/logrotate.conf 文件就可以了。

四、使用include 选项覆盖缺省配置

当 /etc/logrotate.conf 读入文件时，include 指定的文件中的转储参数将覆盖缺省的参数，如下例：

# linuxconf 的参数

/var/log/htmlaccess.log

{ errors jim

notifempty

nocompress

weekly

prerotate

/usr/bin/chattr -a /var/log/htmlaccess.log

endscript

postrotate

/usr/bin/chattr +a /var/log/htmlaccess.log

endscript

}

/var/log/netconf.log

{ nocompress

monthly

}

在这个例子中，当 /etc/logrotate.d/linuxconf 文件被读入时，下面的参数将覆盖/etc/logrotate.conf中缺省的参数。

Notifempty

errors jim

五、为指定的文件配置转储参数

经常需要为指定文件配置参数，一个常见的例子就是每月转储/var/log/wtmp。为特定文件而使用的参数格式是：

# 注释

/full/path/to/file

{

option(s)

}

下面的例子就是每月转储 /var/log/wtmp 一次：

#Use logrotate to rotate wtmp

/var/log/wtmp

{

monthly

rotate 1

}

六、其他需要注意的问题

1、尽管花括号的开头可以和其他文本放在同一行上，但是结尾的花括号必须单独成行。

2、使用 prerotate 和 postrotate 选项

下面的例子是典型的脚本 /etc/logrotate.d/syslog，这个脚本只是对

/var/log/messages 有效。

/var/log/messages

{

prerotate

/usr/bin/chattr -a /var/log/messages

endscript

postrotate

/usr/bin/kill -HUP syslogd

/usr/bin/chattr +a /var/log/messages

endscript

}

第一行指定脚本对 /var/log messages 有效

花ê哦阅诓康慕疟驹诵杏? /var/log/messages

prerotate 命令指定转储以前的动作/usr/bin/chattr -a 去掉/var/log/messages文件的“只追加”属性 endscript 结束 prerotate 部分的脚本postrotate 指定转储后的动作

/usr/bin/killall -HUP syslogd

用来重新初始化系统日志守护程序 syslogd

/usr/bin/chattr +a /var/log/messages

重新为 /var/log/messages 文件指定“只追加”属性，这样防治程序员或用户覆盖此文件。

最后的 endscript 用于结束 postrotate 部分的脚本

3、logrotate 的运行分为三步：

判断系统的日志文件，建立转储计划以及参数，通过cron daemon 运行下面的代码是 Red Hat Linux 缺省的crontab 来每天运行logrotate。

#/etc/cron.daily/logrotate

#! /bin/sh

/usr/sbin/logrotate /etc/logrotate.conf

4、/var/log/messages 不能产生的原因：

这种情况很少见，但是如果你把/etc/services 中的 514/UDP 端口关掉的话，这个文件就不能产生了。 

以上是网上的一篇中文说明。

个人觉得比较有用的一个例子：
/etc/logrotate.d/xxx
/home/zhoudh/test/yyy {
    rotate 2
    size 100
    copytruncate 
    compress
    delaycompress 
}
logrotate是个强大的系统软件，它对日志文件（只要文件名固定的）有着一套完整的操作模式，譬如：转储、邮件和压缩等等；但是它也有那么点瑕疵：就是转储的时候，文件大小经常不是预期的，譬如，设置成size 1024，那么转储的时候文件大小可能已经上兆了。原因很简单，因为logrotate是个cron任务，它只能每天（最小轮询单位）轮询一次，至于在这一天内文件大小超过1024，它也无能为力。不管怎么说，logrotate是个非常实用的工具，只要对log临时需要（测试）或要求不高，都可以采用。以下是我对logrotate的理解和整理。

logrotate

LOGROTATE(8)             System Administrator’s Manual            LOGROTATE(8)

NAME

       logrotate - rotates, compresses, and mails system logs

SYNOPSIS

       logrotate [-dv] [-f|--force] [-s|--state file] config_file+

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  multiple  times  in  one  day unless the criterium for that log is       based on the log’s size and logrotate is being run multiple times  each       day, or unless the -f or -force option is used.       Any number of config files may be given on the command line. Later con-       fig files may override the options given in earlier files, so the order       in  which  the logrotate config files are listed in is important.  Nor-       mally, 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.

描述：

       为了简化对产生大量日志文件的各种系统的管理，logrotate从而被设计出来。它可以       自动转储、压缩、删除和邮件这些日志。每个日志文件可以在每天，每星期，每月或太       大了的时候被处理。
       通常，logrotate是一个每天执行一次的cron任务。除非被操作的日志文件是以大小处理       的，并且在一天内logrotate被执行多次，或是使用了选项-f或-force，每天logrotate       不会多次修改一个文件。       命令行可以包含任意数量的配置文件。后面的配置文件可能会覆盖前面的配置文件给出的       选项，所以logrotate列出的配置文件顺序是很重要的。通常，如果需要包含其它配置文       件信息，那么应该用一个单一的配置文件。根据下面更多的信息，通过使用include导向       来完成这个。假如命令行上给出的是个目录，那么在这个目录下的文件都被看作是一个配       置文件。       如果命令行不包含任意选项，那么logrotate会打印出它的版本和版权信息，以及一段短       小的用法摘要。

OPTIONS

       -v     Turn on verbose mode.       -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 logrotate, or if old log files have been  removed  by              hand,  as  the  new files will be created, and logging will con-              tinue correctly.       -m, --mail               Tells logrotate which command to use  when  mailing  logs.  This              command  should accept two arguments: 1) the subject of the mes-              sage, 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 /bin/mail -s.       -s, --state               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/sta-              tus.       --usage              Prints a short usage message.

选项：

       -v     打开冗长模式。       -d     打开调试模式，并且隐式打开冗长模式-v。在调试模式下，日志文件和log-            rotate状态文件不会有变化。        -f, --force            告诉logrotate强制轮调，即使它不认为这是必要的。有时这是很有用的，              譬如logrotate增加了新的入口；又如假设旧的日志文件被手动删除了，这              样新的日志文件需要创建出来，保证正常写日志。       -m, --mail             告诉logrotate当邮件日志时调用command。这个command需要包含2个参数：              1) 消息的主题，和 2) 接收者。这个command必须从标准输入上读出消息，然              后发邮件给接收者。默认发邮件命令是/bin/mail -s。        -s, --state             告诉logrotate使用备用的状态文件。当另一个用户正在用logrotate管理大              量的日志文件时，这是非常有用的。默认的状态文件是/var/lib/logrotate            /status。       --usage            打印简要的用法信息。

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 over-       ride global ones, and later  definitions  override  earlier  ones)  and       specify  a  logfile  to  rotate. A simple configuration file looks like       this:       # sample logrotate configuration file       compress       /var/log/messages {           rotate 5           weekly           postrotate                                     /sbin/killall -HUP syslogd           endscript       }       "/var/log/httpd/access.log" /var/log/httpd/error.log {           rotate 5           mail www@my.org           size=100k           sharedscripts           postrotate                                     /sbin/killall -HUP httpd           endscript       }       /var/log/news/news.crit {           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  com-       pressed 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 files defined 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.    They   are       rotated whenever is grows over 100k is size, and the old logs files are       mailed (uncompressed) to www@my.org after going  through  5  rotations,       rather  then 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 the double quotes       around the first filename at  the  beginning  of  this  section  allows       logrotate  to rotate logs with spaces in the name. 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 con-       sidered a single rotation directive and if errors occur for  more  then       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).       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 by default.              See also nocompress.       compresscmd              Specifies which command to  use  to  compress  log  files.   The              default is gzip.  See also compress.       uncompresscmd              Specifies  which  command  to  use to uncompress log files.  The              default is gunzip.       compressext              Specifies which extension to use on compressed logfiles, if com-              pression 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, is "-9" (maximum com-              pression).       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 pare 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 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 can not 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  log-              ging  data  might be lost.  When this option is used, the create              option will have no effect, as the old log file stays in  place.       create 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.       delaycompress              Postpone  compression of the previous log file to the next rota-              tion cycle.  This has only effect when used in combination  with              compress.   It  can be used when some program can not be told to              close its logfile and thus might continue writing to the  previ-              ous log file for some time.       extension ext              Log  files  are given the final extension ext after rotation. If              compression is used, the compression  extension  (normally  .gz)              appears after ext.       ifempty              Rotate  the  log  file  even  if  it  is  empty,  overiding  the              notifempty option (ifempty is the default).       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, as specified by  the  tabooext              directive.  The include directive may not appear inside of a log              file definition.       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.       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).       missingok              If the log file is missing, go on to the next one without  issu-              ing 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 with gzip. 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).       nomail Don’t 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 same directory the log normally  resides              in (this overrides the olddir option).       nosharedscripts              Run  prerotate  and postrotate scripts for every script which is              rotated (this is the default, and  overrides  the  sharedscripts              option).       notifempty              Do not rotate the log if it is empty (this overrides the ifempty              option).       olddir 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 overriden 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 of a log              file definition.  See prerotate as well.       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 of a log file definition.  See              postrotate as well.       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 pre-              rotate  script is run and only if at least one log will actually              be rotated. These directives may only appear  inside  of  a  log              file definition. See lastaction as well.       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 of a log file              definition. See lastaction as well.       rotate count              Log files are rotated   times  before  being  removed  or              mailed to the address specified in a mail directive. If count is              0, old versions are removed rather then rotated.       size size              Log files are rotated when they grow bigger then size bytes.  If              size  is  followed by M, the size if assumed to be in megabytes.              If the k is used, the size is in kilobytes. So  size  100,  size              100k, and size 100M are all valid.       sharedscripts              Normally,  prescript and postscript scripts are run for each log              which is rotated, meaning that a single script may be run multi-              ple  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. This              option overrides the nosharedscripts option and  implies  create              option.       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              count directive.       tabooext [+] list              The current taboo extension list is  changed  (see  the  include              directive  for information on the taboo extensions). If a + pre-              cedes 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,              and ~.       weekly Log  files  are  rotated if the current weekday is less then the              weekday of the last rotation or if more then a week  has  passed              since  the  last rotation. This is normally the same as rotating              logs on the first day of the week, but it works better if logro-              tate is not run every night.

FILES

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

SEE ALSO

       gzip(1)

AUTHORS

       Erik Troan <ewt@redhat.com>       Preston Brown <pbrown@redhat.com>4th Berkeley Distribution       Wed Nov 5 2002                    LOGROTATE(8)

以上是linux man手册上的logrotate。

系统管理员可以使用logrotate 程序用来管理系统中的最新的事件。logrotate 还可以用来备份日志文件，本篇将通过以下几部分来介绍

日志文件的管理：

1、logrotate 配置

2、缺省配置 logrotate

3、使用include 选项读取其他配置文件

4、使用include 选项覆盖缺省配置

5、为指定的文件配置转储参数

一、logrotate 配置

logrotate 程序是一个日志文件管理工具。用来把旧的日志文件删除，并创建新的日志文件，我们把它叫做“转储”。我们可以根据日志文件的大小，也可以根据其天数来转储，这个过程一般通过 cron 程序来执行。

logrotate 程序还可以用于压缩日志文件，以及发送日志到指定的E-mail 。

logrotate 的配置文件是 /etc/logrotate.conf。主要参数如下表：

参数 功能

compress 通过gzip 压缩转储以后的日志

nocompress 不需要压缩时，用这个参数

copytruncate 用于还在打开中的日志文件，把当前日志备份并截断

nocopytruncate 备份日志文件但是不截断

create mode owner group 转储文件，使用指定的文件模式创建新的日志文件

nocreate 不建立新的日志文件

delaycompress 和 compress 一起使用时，转储的日志文件到下一次转储时才压缩

nodelaycompress 覆盖 delaycompress 选项，转储同时压缩。

errors address 专储时的错误信息发送到指定的Email 地址

ifempty 即使是空文件也转储，这个是 logrotate 的缺省选项。

notifempty 如果是空文件的话，不转储

mail address 把转储的日志文件发送到指定的E-mail 地址

nomail 转储时不发送日志文件

olddir directory 转储后的日志文件放入指定的目录，必须和当前日志文件在同一个文件系统

noolddir 转储后的日志文件和当前日志文件放在同一个目录下

prerotate/endscript 在转储以前需要执行的命令可以放入这个对，这两个关键字必须单独成行

postrotate/endscript 在转储以后需要执行的命令可以放入这个对，这两个关键字必须单独成行

daily 指定转储周期为每天

weekly 指定转储周期为每周

monthly 指定转储周期为每月

rotate count 指定日志文件删除之前转储的次数，0 指没有备份，5 指保留5 个备份

tabootext [+] list 让logrotate 不转储指定扩展名的文件，缺省的扩展名是：.rpm-orig, .rpmsave, v, 和 ~

size size 当日志文件到达指定的大小时才转储，Size 可以指定 bytes (缺省)以及KB (sizek)或者MB (sizem).

二、缺省配置 logrotate

logrotate 缺省的配置募??/etc/logrotate.conf。

Red Hat Linux 缺省安装的文件内容是：

# see "man logrotate" for details

# rotate log files weekly

weekly

# keep 4 weeks worth of backlogs

rotate 4

# send errors to root

errors root

# create new (empty) log files after rotating old ones

create

# uncomment this if you want your log files compressed

#compress

1

# RPM packages drop log rotation information into this directory

include /etc/logrotate.d

# no packages own lastlog or wtmp --we'll rotate them here

/var/log/wtmp {

monthly

create 0664 root utmp

rotate 1

}

/var/log/lastlog {

monthly

rotate 1

}

# system-specific logs may be configured here

缺省的配置一般放在logrotate.conf 文件的最开始处，影响整个系统。在本例中就是前面12行。

第三行weekly 指定所有的日志文件每周转储一次。

第五行 rotate 4 指定转储文件的保留 4份。

第七行 errors root 指定错误信息发送给root。

第九行create 指定 logrotate 自动建立新的日志文件，新的日志文件具有和

原来的文件一样的权限。

第11行 #compress 指定不压缩转储文件，如果需要压缩，去掉注释就可以了。

三、使用include 选项读取其他配置文件

include 选项允许系统管理员把分散到几个文件的转储信息，集中到一个

主要的配置文件。当 logrotate 从logrotate.conf 读到include 选项时，会从指定文件读入配置信息，就好像他们已经在/etc/logrotate.conf 中一样。

第13行 include /etc/logrotate.d 告诉 logrotate 读入存放在/etc/logrotate.d 目录中的日志转储参数，当系统中安装了RPM 软件包时，使用include 选项十分有用。RPM 软件包的日志转储参数一般存放在/etc/logrotate.d 目录。

include 选项十分重要，一些应用把日志转储参数存放在 /etc/logrotate.d 。

典型的应用有：apache, linuxconf, samba, cron 以及syslog。

这样，系统管理员只要管理一个 /etc/logrotate.conf 文件就可以了。

四、使用include 选项覆盖缺省配置

当 /etc/logrotate.conf 读入文件时，include 指定的文件中的转储参数将覆盖缺省的参数，如下例：

# linuxconf 的参数

/var/log/htmlaccess.log

{ errors jim

notifempty

nocompress

weekly

prerotate

/usr/bin/chattr -a /var/log/htmlaccess.log

endscript

postrotate

/usr/bin/chattr +a /var/log/htmlaccess.log

endscript

}

/var/log/netconf.log

{ nocompress

monthly

}

在这个例子中，当 /etc/logrotate.d/linuxconf 文件被读入时，下面的参数将覆盖/etc/logrotate.conf中缺省的参数。

Notifempty

errors jim

五、为指定的文件配置转储参数

经常需要为指定文件配置参数，一个常见的例子就是每月转储/var/log/wtmp。为特定文件而使用的参数格式是：

# 注释

/full/path/to/file

{

option(s)

}

下面的例子就是每月转储 /var/log/wtmp 一次：

#Use logrotate to rotate wtmp

/var/log/wtmp

{

monthly

rotate 1

}

六、其他需要注意的问题

1、尽管花括号的开头可以和其他文本放在同一行上，但是结尾的花括号必须单独成行。

2、使用 prerotate 和 postrotate 选项

下面的例子是典型的脚本 /etc/logrotate.d/syslog，这个脚本只是对

/var/log/messages 有效。

/var/log/messages

{

prerotate

/usr/bin/chattr -a /var/log/messages

endscript

postrotate

/usr/bin/kill -HUP syslogd

/usr/bin/chattr +a /var/log/messages

endscript

}

第一行指定脚本对 /var/log messages 有效

花ê哦阅诓康慕疟驹诵杏? /var/log/messages

prerotate 命令指定转储以前的动作/usr/bin/chattr -a 去掉/var/log/messages文件的“只追加”属性 endscript 结束 prerotate 部分的脚本postrotate 指定转储后的动作

/usr/bin/killall -HUP syslogd

用来重新初始化系统日志守护程序 syslogd

/usr/bin/chattr +a /var/log/messages

重新为 /var/log/messages 文件指定“只追加”属性，这样防治程序员或用户覆盖此文件。

最后的 endscript 用于结束 postrotate 部分的脚本

3、logrotate 的运行分为三步：

判断系统的日志文件，建立转储计划以及参数，通过cron daemon 运行下面的代码是 Red Hat Linux 缺省的crontab 来每天运行logrotate。

#/etc/cron.daily/logrotate

#! /bin/sh

/usr/sbin/logrotate /etc/logrotate.conf

4、/var/log/messages 不能产生的原因：

这种情况很少见，但是如果你把/etc/services 中的 514/UDP 端口关掉的话，这个文件就不能产生了。 

以上是网上的一篇中文说明。

个人觉得比较有用的一个例子：
/etc/logrotate.d/xxx
/home/zhoudh/test/yyy {
    rotate 2
    size 100
    copytruncate 
    compress
    delaycompress 
}