RHEL 7 uses system temp files to

 

Managing temporary files with systemd-tmpfiles on Red Hat

Why the files in /tmp directory gets deleted periodically

 

For CentOS/RHEL7

cd /usr/lib/tmpfiles.d/tmp.conf

# cat /usr/lib/tmpfiles.d/tmp.conf
# 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

For CentOS/RHEL6

cd /etc/cron.daily/tmpwatch

# cat /etc/cron.daily/tmpwatch
#! /bin/sh
flags=-umc
/usr/sbin/tmpwatch "$flags" -x /tmp/.X11-unix -x /tmp/.XIM-unix \
	-x /tmp/.font-unix -x /tmp/.ICE-unix -x /tmp/.Test-unix \
	-X '/tmp/hsperfdata_*' -X '/tmp/.hdb*lock' -X '/tmp/.sapstartsrv*.log' \
	-X '/tmp/pymp-*' 10d /tmp

# man tmpwatch