日志管理

谁践踏了优雅 2022-12-02 12:28 238阅读 0赞

## 一 日志相关文件 ##

#很关键
    [root@client01 ~]# ls /var/log/
    anaconda.ifcfg.log    anaconda.xlog      btmp           dmesg       maillog            secure            wtmp
    anaconda.log          anaconda.yum.log   btmp-20130805  dmesg.old  maillog-20130805  secure-20130805   yum.log
    anaconda.program.log  audit              ConsoleKit     dracut.log messages           spooler
    anaconda.storage.log  boot.log           cron          httpd       messages-20130805  spooler-20130805
    anaconda.syslog       boot.log-20130805  cron-20130805 lastlog     rhsm               tallylog
     
    #关键日志，大部分记录在里面
    [root@client01 ~]# ls /var/log/messages
    /var/log/messages
          
    #系统启动，硬件相关日志
    [root@client01 ~]# ls /var/log/dmesg*
    /var/log/dmesg  /var/log/dmesg.old
     
    #登录安全相关日志
    [root@client01 ~]# ls /var/log/secure
    /var/log/secure
     
    #使用ssh登录，输入错误密码
    [root@larrywen opt]# ssh 192.168.1.11
    root@192.168.1.11's password:
    Permission denied, please try again.
    root@192.168.1.11's password:
    Permission denied, please try again.
     
    #监控文件，可以看到刚才输入的错误密码已经记录下来了
    [root@client01 ~]# tail -f /var/log/secure
    [root@client01 ~]# tail -n 4/var/log/secure
    Aug 5 14:46:13 client01 sshd[2796]: pam_unix(sshd:auth): authenticationfailure; logname= uid=0 euid=0 tty=ssh ruser= rhost=192.168.1.1  user=root
    Aug 5 14:46:15 client01 sshd[2796]: Failed password for root from192.168.1.1 port 50116 ssh2
    Aug 5 14:46:23 client01 unix_chkpwd[2800]: password check failed for user(root)
    Aug 5 14:46:25 client01 sshd[2796]: Failed password for root from192.168.1.1 port 50116 ssh2
     
    #邮件相关日志
    [root@larrywen opt]# ls /var/log/maillog
    /var/log/maillog
     
    #登录信息日志
    [root@client01 ~]# ls /var/log/lastlog
    #最后登录的信息
    [root@client01 ~]# ls /var/log/lastlog
    /var/log/lastlog
    [root@client01 ~]# last
    #最后登录错误的信息
    [root@client01 ~]# lastb
     
    #SELINUX相关日志
    [root@client01 ~]# ls /var/log/audit/
    audit.log
     
    [root@client01 ~]# ls /var/log/maillog*
    /var/log/maillog  /var/log/maillog-20130805
    #之前日志的备份，一个星期切换一次，会自动备份
    maillog-20130805
     
    [root@larrywen 0805]# ls /var/log/maillog*
    /var/log/maillog  /var/log/maillog-20130729  /var/log/maillog-20130805
    [root@larrywen 0805]# ls /var/log/boot.log*
    /var/log/boot.log  /var/log/boot.log-20130729  /var/log/boot.log-20130805

## 二 日志相关服务 ##

[root@client01 ~]# ps -ef|grep log
    #系统日志服务
    root      959     1  0 08:49 ?        00:00:00 /sbin/rsyslogd -c 4
    root     1133     1  0 08:49 ?        00:00:00 login -- root    
    root     2811  2776  0 14:54 pts/0    00:00:00 grep log
     
    [root@client01 ~]# /etc/init.d/rsyslogrestart
    Shutting down system logger:                               [  OK  ]
    Starting system logger:                                    [  OK  ]
     
     
    #rsyslog：日志记录的位置，指定输出文件
    #日志级别：Debug Warning

## 三 实验：日志转移（一台机器的日志备份到另一台机器） ##

### client01： ###

[root@client01 ~]# ls /etc/*log*
    /etc/csh.login  /etc/login.defs  /etc/logrotate.conf  /etc/rsyslog.conf
     
    /etc/logrotate.d:
    dracut httpd  subscription-manager  syslog up2date  yum
    [root@client01 ~]# ls /etc/rsyslog.conf
    /etc/rsyslog.conf
    [root@client01 ~]# vim /etc/rsyslog.conf
     
    #模块：实现某个功能的程序
     
    #不要急着写，支持异步写。等到一定量的时候才写，延迟写（负号的含义）
    -/var/log/maillog
     
    #修改文件
    [root@client01 ~]# vim /etc/rsyslog.conf
     
    [root@client01 ~]# grep "hongyi"/etc/rsyslog.conf -n
    60:local3.*                                      /var/log/hongyi.log
    #重启服务
    [root@client01 ~]# /etc/init.d/rsyslogrestart
    Shutting down system logger:                               [  OK  ]
    Starting system logger:                                    [  OK  ]
    #可以查看到生成了这个文件
    [root@client01 ~]# ls /var/log/hongyi.log
    /var/log/hongyi.log
    #写日志
    [root@client01 ~]# logger -p"local3.info" "this is test"
    [root@client01 ~]# cat /var/log/hongyi.log
    Aug 5 15:17:00 client01 root: this is test
    #我们写local2.info，发现没有记录
    [root@client01 ~]# logger -p"local2.info" "this is test"
    [root@client01 ~]# cat /var/log/hongyi.log
    Aug 5 15:17:00 client01 root: this is test
     
    [root@client01 ~]# logger --help
    logger: invalid option -- '-'
    usage: logger [-is] [-f file] [-p pri] [-ttag] [-u socket] [ message ... ]
     
    #性能
     
    #一台机器上的文件保存到另一台机器上
    [root@serv02 ~]# grep "UDP" /etc/rsyslog.conf  -n -A1
    12:# Provides UDP syslog reception
    13-$ModLoad imudp.so
    14:$UDPServerRun 514
    15-
    [root@serv02 ~]# grep "local3.*"/etc/rsyslog.conf  -n
    59:local3.*                                      /tmp/up.log
    [root@larrywen 0805]# man rsyslog.conf

### serv01: ###

#rsyslog.conf做如下配置
    [root@serv01 ~]# grep local3/etc/rsyslog.conf -n
    #192.168.1.12是serv02的IP
    #@：UDP 服务
    #@@：TCP服务
    60:local3.*     @192.168.1.12
    #重启服务
    [root@serv01 ~]# /etc/init.d/rsyslogrestart
    Shutting down system logger:                               [  OK  ]
    Starting system logger:                                    [  OK  ]
    #Serv02配置完后，输出日志到第二台机器
    [root@serv01 ~]# logger -p"local3.info" "hello,world"

### serv02: ###

#rsyslog.conf文件做如下配置
    [root@serv02 ~]# cat -n/etc/rsyslog.conf|sed "8,9p;/local3/p"  -n
        8  $ModLoad imuxsock.so    # provides support for local system logging(e.g. via logger command)
        9  $ModLoad imklog.so # provides kernel logging support (previouslydone by rklogd)
    59   local3.*     /tmp/up.log
    #重启服务
    [root@serv02 ~]# /etc/init.d/rsyslogrestart
    Shutting down system logger:                               [  OK  ]
    Starting system logger:                                    [  OK  ]
    #查看文件可以看到
    [root@serv02 ~]# cat /tmp/up.log
    Aug 5 15:31:38 serv01 root: hello,world
     
    #日志备份

## 四 定时计划任务 ##

[root@client01 ~]# yum install at -y
    [root@client01 ~]# at now +3 minutes
    at> echo "hello,wolrd" >/opt/aa01.txt
    at> <EOT>
    job 2 at 2013-08-05 16:20
    Can't open /var/run/atd.pid to signal atd.No atd running?
    [root@client01 ~]# /etc/init.d/atd start
    Starting atd:                                              [  OK  ]
    #相对当前时间
    [root@client01 ~]# at now +3 minutes
    at> echo "hello,wolrd" >/opt/aa01.txt
    at> <EOT>
    job 3 at 2013-08-05 16:21
    [root@client01 ~]# at -l
    3     2013-08-0516:21 a root：  
    2     2013-08-0516:20 a root
    root@client01 opt]# ll
    total 20
    -rw-r--r--. 1 root root    12 Aug 5 16:20 aa01.txt
    drwx------. 2 root root 16384 Jul 23 00:54lost+found
     
    #支持分钟 小时 天
    [root@client01 ~]# at now +1 days
     
     
    [root@client01 opt]# at 16:28 08/05/2013
    at> echo "hello,uplooking"> /opt/aa02.txt
    at> <EOT>
    job 4 at 2013-08-05 16:28
    [root@client01 opt]# at -l
    4     2013-08-0516:28 a root
     
    [root@client01 opt]# at 18:20 08/06/2013
    at> rm -rf /*<EOT>
    job 5 at 2013-08-06 18:20
    [root@client01 opt]# at -l
    5     2013-08-0618:20 a root
    4     2013-08-0516:28 a root
     
    [root@client01 opt]# at --help
    at: invalid option -- '-'
    Usage: at [-V] [-q x] [-f file] [-mldbv]time
          at -c job ...
          atq [-V] [-q x]
          atrm [-V] job ...
          batch
    #移除
    [root@client01 opt]# atrm 5
    #列出详细的任务
    [root@client01 opt]# at -l
    4     2013-08-0516:28 a root
     
    #执行完后自动清除，本次有效
     
    #crontab：循环有效
    [root@client01 opt]# vim /etc/crontab
       ** * * * echo `date` >> /opt/aa03.txt
    #添加规则
    [root@client01 opt]# crontab -e
    no crontab for root - using an empty one
    crontab: installing new crontab
     
    30 18 * * * init 0
    1 */2 10-20 7,8 5 wall "Have aholiday"
    #列出所有的任务
    [root@client01 opt]# crontab -l
    * * * * * echo `date` >>/opt/aa03.txt
    30 18 * * * init 0
    [root@client01 opt]# crontab --help
    crontab: invalid option -- '-'
    crontab: usage error: unrecognized option
    usage:    crontab[-u user] file
           crontab[-u user] [ -e | -l | -r ]
                  (defaultoperation is replace, per 1003.2)
           -e    (edit user's crontab)
           -l     (list user's crontab)
           -r    (delete user's crontab)
           -i     (prompt before deleting user's crontab)
           -s    (selinux context)
     
    #查看编写的文件
    [root@client01 opt]# cd /var/spool/
    [root@client01 spool]# ls
    anacron at  cron  lpd mail  plymouth  postfix up2date
    [root@client01 spool]# cd cron/
    [root@client01 cron]# ll
    total 4
    -rw-------. 1 root root 58 Aug  5 16:37 root
    [root@client01 cron]# cat root
    * * * * * echo `date` >>/opt/aa03.txt
    30 18 * * * init 0
    [root@client01 cron]# cd /etc/cron.
    cron.d/       cron.daily/   cron.deny    cron.hourly/  cron.monthly/cron.weekly/
          
    #每天执行的
    [root@client01 cron]# cat/etc/cron.d/0hourly
    SHELL=/bin/bash
    PATH=/sbin:/bin:/usr/sbin:/usr/bin
    MAILTO=root
    HOME=/
    01 * * * * root run-parts /etc/cron.hourly
     
    #每个小时执行的
    [root@client01 cron]# cat/etc/cron.hourly/0anacron
    #!/bin/bash
    #in case file doesn't exist
    if test -r /var/spool/anacron/cron.daily;then
       day=`cat /var/spool/anacron/cron.daily`
    fi
    if [ `date +%Y%m%d` = "$day" ];then
       exit 0;
    fi
     
    # in case anacron is already running,
    # there will be log (daemon won't berunning twice).
    if test -x /usr/bin/on_ac_power; then
       /usr/bin/on_ac_power &> /dev/null
       if test $? -eq 1; then
       exit 0
       fi
    fi
    /usr/sbin/anacron -s
     
    #查看每天执行的配置文件
    [root@client01 cron]# cat/etc/cron.daily/logrotate
    #!/bin/sh
     
    /usr/sbin/logrotate /etc/logrotate.conf>/dev/null 2>&1
    EXITVALUE=$?
    if [ $EXITVALUE != 0 ]; then
       /usr/bin/logger -t logrotate "ALERT exited abnormally with[$EXITVALUE]"
    fi
    exit 0
     
    #查看syslog文件，可以看到日志的创建过程
    [root@client01 logrotate.d]# cat syslog
    /var/log/messages /var/log/secure/var/log/maillog /var/log/spooler /var/log/boot.log /var/log/cron {
       sharedscripts
       postrotate
           /bin/kill-HUP `cat /var/run/syslogd.pid 2> /dev/null` 2> /dev/null || true
       endscript
    }
     
    #可以对日志的相关文件进行配置
    [root@client01 cron]# cat/etc/logrotate.conf
    # see "man logrotate" for details
    # rotate log files weekly
    weekly
     
    # keep 4 weeks worth of backlogs
    rotate 4
     
    # create new (empty) log files afterrotating old ones
    create
     
    # use date as a suffix of the rotated file
    dateext
     
    # uncomment this if you want your log filescompressed
    #compress
     
    # RPM packages drop log rotationinformation into this directory
    include /etc/logrotate.d
     
    # no packages own wtmp and btmp -- we'llrotate them here
    /var/log/wtmp {
       monthly
       create 0664 root utmp
           minsize1M
       rotate 1
    }
     
    /var/log/btmp {
       missingok
       monthly
       create 0600 root utmp
       rotate 1
    }
     
    # system-specific logs may be also beconfigured here.

## 五 模拟日志文件的拷贝 ##

#从man中进行示例的拷贝
    [root@client01 logrotate.d]# manlogrotate.conf
     
    #编辑文件
    [root@client01 logrotate.d]# vim/etc/logrotate.conf
    [root@client01 logrotate.d]# cat/etc/logrotate.conf
    /opt/hongyi.log {
       monthly
       rotate 2
       olddir /opt/old
       missingok
       create 0600 root hongyi
       nocompress
    }
    #创建用户
    [root@client01 logrotate.d]# useradd hongyi
    #创建目录
    [root@client01 logrotate.d]# mkdir /opt/old
    #创建文件
    [root@client01 logrotate.d]# touch/opt/hongyi.log
    #编辑文件
    [root@client01 logrotate.d]# vim/opt/hongyi.log
    [root@client01 logrotate.d]# ls /opt
    aa03.txt hongyi.log  old
     
    [root@client01 logrotate.d]# logrotate--help
    Usage: logrotate [OPTION...]<configfile>
      -d,--debug               Don't do anything,just test (implies -v)
      -f,--force               Force file rotation
      -m,--mail=command        Command to sendmail (instead of `/bin/mail')
      -s,--state=statefile     Path of state file
      -v,--verbose             Display messagesduring rotation
     
    Help options:
      -?,--help                Show this helpmessage
     —usage                   Displaybrief usage message
    #强制使配置文件生效
    [root@client01 logrotate.d]# logrotate -f/etc/logrotate.conf
    [root@client01 logrotate.d]# ls /opt
    aa03.txt hongyi.log  old
    #可以看到已经生成了文件
    [root@client01 logrotate.d]# ls /opt/old/
    hongyi.log-20130805
    #日志轮寻
    #日志切换
     
    [root@client01 ~]# ls /etc/cron.d
    cron.d/    cron.daily/ cron.deny
    #查看每天切换的 
    [root@client01 ~]# ls /etc/cron.daily/
    logrotate makewhatis.cron  rhsm-complianced
    [root@client01 ~]# cat/etc/cron.daily/logrotate
    #!/bin/sh
     
    /usr/sbin/logrotate /etc/logrotate.conf>/dev/null 2>&1
    EXITVALUE=$?
    if [ $EXITVALUE != 0 ]; then
       /usr/bin/logger -t logrotate "ALERT exited abnormally with[$EXITVALUE]"
    fi
    exit 0
    [root@client01 ~]# cat /etc/logrotate.conf
    # see "man logrotate" for details
    # rotate log files weekly
    weekly
     
    # keep 4 weeks worth of backlogs
    rotate 4
     
    # create new (empty) log files afterrotating old ones
    create
     
    # use date as a suffix of the rotated file
    dateext
     
    # uncomment this if you want your log filescompressed
    #compress
     
    # RPM packages drop log rotationinformation into this directory
    include /etc/logrotate.d
     
    # no packages own wtmp and btmp -- we'llrotate them here
    /var/log/wtmp {
       monthly
       create 0664 root utmp
           minsize1M
       rotate 1
    }
     
    /var/log/btmp {
       missingok
       monthly
       create 0600 root utmp
       rotate 1
    }
     
    /opt/hongyi.log {
       monthly
       rotate 2
       olddir /opt/old
       missingok
       create 0600 root hongyi
       nocompress
    }
     
    # system-specific logs may be also beconfigured here.
    [root@client01 ~]# cd /etc/lo
    localtime       login.defs      logrotate.conf  logrotate.d/   
    [root@client01 ~]# cd /etc/logrotate.d/
    [root@client01 logrotate.d]# ll
    total 24
    -rw-r--r--. 1 root root 103 Apr 27  2011 dracut
    -rw-r--r--. 1 root root 185 Jun 24  2010 httpd
    -rw-r--r--. 1 root root  71 May 5  2011 subscription-manager
    -rw-r--r--. 1 root root 228 May 20  2009 syslog
    -rw-r--r--. 1 root root  32 Apr 8  2010 up2date
    -rw-r--r--. 1 root root 100 Apr 29  2011 yum
     
    #程序切换 日志切换
    #日志：很重要
          
    #设置日期
    [root@client01 opt]# date -s"2013-08-07"
    Wed Aug 7 00:00:00 CST 2013
    #强制使文件生效，v显示过程
    [root@client01 opt]# logrotate -fv/etc/logrotate.conf
    reading config file /etc/logrotate.conf
    including /etc/logrotate.d
    reading config file dracut
    reading config info for /var/log/dracut.log
    reading config file httpd
    reading config info for /var/log/httpd/*log
    reading config file subscription-manager
    reading config info for /var/log/rhsm/*.log
    reading config file syslog
    reading config info for /var/log/messages/var/log/secure /var/log/maillog /var/log/spooler /var/log/boot.log/var/log/cron
    reading config file up2date
    reading config info for /var/log/up2date
    reading config file yum
    reading config info for /var/log/yum.log
    reading config info for /var/log/wtmp
    reading config info for /var/log/btmp
    reading config info for /opt/hongyi.log
    olddir is now /opt/old
     
    Handling 9 logs
     
    rotating pattern: /var/log/dracut.log  forced from command line (4 rotations)
    empty log files are not rotated, old logsare removed
    considering log /var/log/dracut.log
      logdoes not need rotating
     
    rotating pattern: /var/log/httpd/*log  forced from command line (4 rotations)
    empty log files are not rotated, old logsare removed
    considering log /var/log/httpd/access_log
      logdoes not need rotating
    considering log /var/log/httpd/error_log
      logdoes not need rotating
    not running postrotate script, since nologs were rotated
     
    rotating pattern: /var/log/rhsm/*.log  forced from command line (4 rotations)
    empty log files are not rotated, old logsare removed
    considering log /var/log/rhsm/rhsmcertd.log
      logdoes not need rotating
    considering log /var/log/rhsm/rhsm.log
      logdoes not need rotating
     
    rotating pattern: /var/log/messages/var/log/secure /var/log/maillog /var/log/spooler /var/log/boot.log/var/log/cron  forced from command line(4 rotations)
    empty log files are rotated, old logs areremoved
    considering log /var/log/messages
      logneeds rotating
    considering log /var/log/secure
      logneeds rotating
    considering log /var/log/maillog
      logneeds rotating
    considering log /var/log/spooler
      logneeds rotating
    considering log /var/log/boot.log
      logneeds rotating
    considering log /var/log/cron
      logneeds rotating
    rotating log /var/log/messages,log->rotateCount is 4
    dateext suffix '-20130807'
    glob pattern '-[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
    rotating log /var/log/secure,log->rotateCount is 4
    dateext suffix '-20130807'
    glob pattern'-[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
    rotating log /var/log/maillog,log->rotateCount is 4
    dateext suffix '-20130807'
    glob pattern'-[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
    rotating log /var/log/spooler,log->rotateCount is 4
    dateext suffix '-20130807'
    glob pattern'-[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
    rotating log /var/log/boot.log,log->rotateCount is 4
    dateext suffix '-20130807'
    glob pattern'-[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
    rotating log /var/log/cron,log->rotateCount is 4
    dateext suffix '-20130807'
    glob pattern'-[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
    fscreate context set to system_u:object_r:var_log_t:s0
    renaming /var/log/messages to/var/log/messages-20130807
    creating new /var/log/messages mode = 0600uid = 0 gid = 0
    fscreate context set tosystem_u:object_r:var_log_t:s0
    renaming /var/log/secure to/var/log/secure-20130807
    creating new /var/log/secure mode = 0600uid = 0 gid = 0
    fscreate context set tosystem_u:object_r:var_log_t:s0
    renaming /var/log/maillog to/var/log/maillog-20130807
    creating new /var/log/maillog mode = 0600uid = 0 gid = 0
    fscreate context set tosystem_u:object_r:var_log_t:s0
    renaming /var/log/spooler to/var/log/spooler-20130807
    creating new /var/log/spooler mode = 0600uid = 0 gid = 0
    fscreate context set tosystem_u:object_r:var_log_t:s0
    renaming /var/log/boot.log to/var/log/boot.log-20130807
    creating new /var/log/boot.log mode = 0644uid = 0 gid = 0
    fscreate context set tosystem_u:object_r:var_log_t:s0
    renaming /var/log/cron to/var/log/cron-20130807
    creating new /var/log/cron mode = 0600 uid= 0 gid = 0
    running postrotate script
     
    rotating pattern: /var/log/up2date  forced from command line (4 rotations)
    empty log files are rotated, old logs areremoved
    considering log /var/log/up2date
      log/var/log/up2date does not exist -- skipping
     
    rotating pattern: /var/log/yum.log  forced from command line (4 rotations)
    empty log files are not rotated, old logsare removed
    considering log /var/log/yum.log
      logdoes not need rotating
     
    rotating pattern: /var/log/wtmp  forced from command line (1 rotations)
    empty log files are rotated, only log files>= 1048576 bytes are rotated, old logs are removed
    considering log /var/log/wtmp
      logneeds rotating
    rotating log /var/log/wtmp,log->rotateCount is 1
    dateext suffix '-20130807'
    glob pattern'-[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
    fscreate context set to system_u:object_r:wtmp_t:s0
    renaming /var/log/wtmp to/var/log/wtmp-20130807
    creating new /var/log/wtmp mode = 0664 uid= 0 gid = 22
    removing old log /var/log/wtmp-20130806
     
    rotating pattern: /var/log/btmp  forced from command line (1 rotations)
    empty log files are rotated, old logs areremoved
    considering log /var/log/btmp
      logneeds rotating
    rotating log /var/log/btmp,log->rotateCount is 1
    dateext suffix '-20130807'
    glob pattern'-[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
    fscreate context set to system_u:object_r:faillog_t:s0
    renaming /var/log/btmp to/var/log/btmp-20130807
    creating new /var/log/btmp mode = 0600 uid= 0 gid = 22
    removing old log /var/log/btmp-20130806
     
    rotating pattern: /opt/hongyi.log  forced from command line (2 rotations)
    olddir is /opt/old, empty log files arerotated, old logs are removed
    considering log /opt/hongyi.log
      logneeds rotating
    rotating log /opt/hongyi.log,log->rotateCount is 2
    dateext suffix '-20130807'
    glob pattern'-[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
    fscreate context set tounconfined_u:object_r:usr_t:s0
    renaming /opt/hongyi.log to/opt/old/hongyi.log-20130807
    creating new /opt/hongyi.log mode = 0600uid = 0 gid = 500
    removing old log/opt/old/hongyi.log-20130805
     
    #可以查看old目录下的文件
    [root@client01 opt]# ls old/
    hongyi.log-20130806  hongyi.log-20130807
    [root@client01 opt]# cat hongyi.log
    #查看文件的权限
    [root@client01 opt]# ll
    total 8
    -rw-r--r--. 1 root root   2436 Aug 7 00:01 aa03.txt
    -rw-------. 1 root hongyi    0 Aug 7 00:00 hongyi.log
    drwxr-xr-x. 2 root root   4096 Aug 7 00:00 old

## 六 crontab——定时任务 ##

#延时执行，系统启动后，检测还没有执行的任务。计划任务
    #什么时候启动机器，什么时候检测
    [root@client01 opt]# cat /etc/anacrontab
    # /etc/anacrontab: configuration file foranacron
     
    # See anacron(8) and anacrontab(5) fordetails.
     
    SHELL=/bin/sh
    PATH=/sbin:/bin:/usr/sbin:/usr/bin
    MAILTO=root
    # the maximal random delay added to thebase delay of the jobs
    RANDOM_DELAY=45
    # the jobs will be started during thefollowing hours only
    START_HOURS_RANGE=3-22
     
    #period in days   delay in minutes   job-identifier   command
    1     5     cron.daily            nicerun-parts /etc/cron.daily
    7     25   cron.weekly         nicerun-parts /etc/cron.weekly
    @monthly 45      cron.monthly              nice run-parts /etc/cron.monthly
     
    #crontab：列出和删除
    [root@client01 opt]# crontab -l
    * * * * * echo `date` >>/opt/aa03.txt
    30 18 * * * init 0
    [root@client01 opt]# crontab --help
    crontab: invalid option -- '-'
    crontab: usage error: unrecognized option
    usage:    crontab[-u user] file
           crontab[-u user] [ -e | -l | -r ]
                  (defaultoperation is replace, per 1003.2)
           -e    (edit user's crontab)
           -l     (list user's crontab)
           -r    (delete user's crontab)
           -i     (prompt before deleting user's crontab)
           -s    (selinux context)
    [root@client01 opt]# crontab -r
    [root@client01 opt]# crontab -l
    no crontab for root

>     我的邮箱：wgbno27@163.com   新浪微博：@Wentasy27         
>       微信公众平台：JustOracle（微信号：justoracle）
>       数据库技术交流群：336882565（加群时验证 From CSDN XXX）
>       Oracle交流讨论组：https://groups.google.com/d/forum/justoracle
>       By Larry Wen

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