Linux下关于/tmp目录的清理规则

[root@sam01 ~]# yum install tmpwatch.x86_64

man tmpwatch

tmpwatch  -  removes files which haven‘t been accessed for a period of time.

By  default, tmpwatch dates files by their atime (access time), not their mtime (modification time).

The  time  parameter  defines the threshold for removing files.
If the file has not been accessed for time, the file is removed.
The time  argument is a number with an optional single-character suffix specifying the units: m for minutes, h for hours, d for  days.
If no suffix is specified, time is in hours.

   -u, --atime
          Make the decision about deleting a file based on the  file‘s
          atime (access time). This is the default.

          Note  that  the periodic updatedb file system scans keep the
          atime of directories recent.

   -m, --mtime
          Make the decision about deleting a file based on the  file‘s
          mtime (modification time) instead of the atime.

   -c, --ctime
          Make  the decision about deleting a file based on the file‘s
          ctime (inode change time) instead of the atime; for directo‐
          ries, make the decision based on the mtime.

   -M, --dirmtime
          Make  the  decision  about deleting a directory based on the
          directory‘s mtime (modification time) instead of the  atime;
          completely ignore atime for directories.

[root@sam01 ~]# tmpwatch --atime 30d /tmp

[root@sam01 ~]# cat /usr/lib/systemd/system/systemd-tmpfiles-clean.timer
#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.

[Unit]
Description=Daily Cleanup of Temporary Directories
Documentation=man:tmpfiles.d(5) man:systemd-tmpfiles(8)

[Timer]
OnBootSec=15min
OnUnitActiveSec=1d

# OnBootSec 表示相对于机器被启动的时间点
# 表示相对于匹配单元(本标签下Unit=指定的单元)最后一次被启动的时间点

[root@sam01 ~]# cat /usr/lib/systemd/system/systemd-tmpfiles-clean.service
#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.

[Unit]
Description=Cleanup of Temporary Directories
Documentation=man:tmpfiles.d(5) man:systemd-tmpfiles(8)
DefaultDependencies=no
Conflicts=shutdown.target
After=systemd-readahead-collect.service systemd-readahead-replay.service local-fs.target time-sync.target
Before=shutdown.target

[Service]
Type=oneshot
ExecStart=/usr/bin/systemd-tmpfiles --clean
IOSchedulingClass=idle

# Type=oneshot 这一选项适用于只执行一项任务、随后立即退出的服务
# 命令文件 /usr/bin/systemd-tmpfiles
# 命令参数 --clean
# 通过定期执行 /usr/bin/systemd-tmpfiles --clean 完成清理

[root@sam01 ~]# /usr/bin/systemd-tmpfiles --help
systemd-tmpfiles [OPTIONS...] [CONFIGURATION FILE...]

Creates, deletes and cleans up volatile and temporary files and directories.

  -h --help                 Show this help
     --version              Show package version
     --create               Create marked files/directories
     --clean                Clean up marked directories
     --remove               Remove marked files/directories
     --boot                 Execute actions only safe at boot
     --prefix=PATH          Only apply rules with the specified prefix
     --exclude-prefix=PATH  Ignore rules with the specified prefix
     --root=PATH            Operate on an alternate filesystem root

# --clean 将会清理被标记的文件目录

[root@sam01 ~]# cat /usr/lib/tmpfiles.d/tmp.conf
#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.

# See tmpfiles.d(5) for details

# Clear tmp directories separately, to make them easier to override
v /tmp 1777 root root 10d
v /var/tmp 1777 root root 30d

# Exclude namespace mountpoints created with PrivateTmp=yes
x /tmp/systemd-private-%b-*
X /tmp/systemd-private-%b-*/tmp
x /var/tmp/systemd-private-%b-*
X /var/tmp/systemd-private-%b-*/tmp


x

在根据"寿命"字段清理过期文件时， 忽略指定的路径及该路径下的所有内容。 可以在"路径"字段中使用shell风格的通配符。 注意，这个保护措施对 r 与 R 无效。

X

在根据"寿命"字段清理过期文件时， 仅忽略指定的路径自身而不包括该路径下的其他内容。 可以在"路径"字段中使用shell风格的通配符。 注意，这个保护措施对 r 与 R 无效。