systemd-tmpfiles-clean.service服务通过systemd-tmpfiles-clean.timer服务定时启动

systemd-tmpfiles-clean.timer服务内容

[root@rmms ~]# 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（默认开机15分钟执行服务）
# 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（默认距离上次执行该服务1天后执行服务）

 systemd-tmpfiles-clean.service服务内容

[root@rmms ~]# 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

/usr/bin/systemd-tmpfiles命令

[root@rmms ~]# /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

/usr/bin/systemd-tmpfiles的配置文件/usr/lib/tmpfiles.d/tmp.conf

[root@rmms ~]# 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

#清理/tmp目录超过10天的内容，但是匹配/tmp/systemd-private-%b-*的目录及其路径下的全部内容会被保留
清理/var/tmp目录超过30天的内容，但是匹配/var/tmp/systemd-private-%b-*的目录及其路径下的全部内容被保留