早上有同事問了下CentOS7下/tmp目錄下文件目錄保留多久，我記得CentOS6下默認好像是30天，CentOS7下不太確認，所以查了下：

[root@kvm02 tmpfiles.d]# cd /usr/lib/tmpfiles.d/
[root@kvm02 tmpfiles.d]# ls
abrt.conf                 iscsi.conf           net-snmp.conf         rpcbind.conf         spice-vdagentd.conf   tuned.conf
cups.conf                 legacy.conf          openlmi-storage.conf  rpm.conf             svnserve.conf         var.conf
cups-lp.conf              libselinux.conf      pam.conf              samba.conf           systemd.conf          x11.conf
etc.conf                  libstoragemgmt.conf  ppp.conf              sap.conf             systemd-nologin.conf
gvfsd-fuse-tmpfiles.conf  lvm2.conf            python.conf           selinux-policy.conf  tmp.conf
initscripts.conf          mdadm.conf           radvd.conf            setroubleshoot.conf  tog-pegasus.conf
[root@kvm02 tmpfiles.d]# 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
# 默認保留時間變為了10天，如果這10天內沒做任何調整，估計會被幹掉
# 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

CentOS6的配置文件是在/etc/cron.daily下，有興趣的朋友自己查下，網上資料比較多

參考資料：

https://developers.redhat.com/blog/2016/09/20/managing-temporary-files-with-systemd-tmpfiles-on-rhel7/

http://blog.csdn.net/zhidetian/article/details/51906335

本文出自 “冰凍vs西瓜” 博客，請務必保留此出處http://molewan.blog.51cto.com/287340/1983723

CentOS7下/tmp目錄裏面的文件默認保留多久