CentOS7下，系统使用systemd管理易变与临时文件，与之相关的系统服务有3个：
systemd-tmpfiles-setup.service ：Create Volatile Files and Directories systemd-tmpfiles-setup-dev.service：Create static device nodes in /dev systemd-tmpfiles-clean.service ：Cleanup of Temporary Directories
配置文件也有3个地方：
/etc/tmpfiles.d/*.conf /run/tmpfiles.d/*.conf /usr/lib/tmpfiles.d/*.conf
/tmp目录的清理规则主要取决于/usr/lib/tmpfiles.d/tmp.conf文件的设定，默认的配置内容为：
# 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 overridev /tmp 1777 root root 7d v /var/tmp 1777 root root 30d # Exclude namespace mountpoints created with PrivateTmp=yesx /tmp/systemd-private-%b-* X /tmp/systemd-private-%b-*/tmp x /var/tmp/systemd-private-%b-* X /var/tmp/systemd-private-%b-*/tmp
如你不想让系统自动清理/tmp下以tomcat开头的目录，那么增加下面这条内容到配置文件中即可：
x /tmp/tomcat.*
