Centos 7
yum -y install yum-utils
# Clear big and old logs
# older than 7 days and greater than 3M or older than 30 days.
find /var -name "*.log" \( \( -size +3M -mtime +7 \) -o -mtime +30 \) -exec truncate {} --size 0 \;
# Cleanup YUM and remove orphan packages
yum clean all
rm -rf /var/cache/yum
package-cleanup --quiet --leaves --exclude-bin
package-cleanup --quiet --leaves --exclude-bin | xargs yum remove -y
rpm --rebuilddb
# Remove old kernels
package-cleanup --oldkernels --count=2
# Remove core dumps
find -regex ".*/core\.[0-9]+$" -delete
# Find files larger than 10 MB
find / -type f -size +10M -not -path "/sys/*" -not -path "/boot/*" -not -path "/proc/*" | xargs du -sh
# delete files larger than 100 MB
# find / -type f -size +100M -exec rm \{\} \;
# Delete non-english locales
localedef --list-archive | grep -v -i ^en | xargs localedef --delete-from-archive
mv /usr/lib/locale/locale-archive /usr/lib/locale/locale-archive.tmpl
build-locale-archive
# if fail , try
# yum reinstall glibc-common
# Cleanup journals
journalctl --disk-usage
# journalctl --vacuum-size=1M
# journalctl --vacuum-time=1months
rm -rf /run/log/journal/*
# Shows you all messages marked as error, critical, alert, or emergency
# 0 emerg
# 1 alert
# 2 crit
# 3 err
# 4 warning
# 5 notice
# 6 info
# 7 debug
journalctl -p 3
# List services
# systemctl list-units --type service
# systemctl list-unit-files --type service
http://everything-virtual.com/2016/05/06/creating-a-centos-7-2-vmware-gold-template/
#!/bin/bash
#stop logging services
/sbin/service rsyslog stop
/sbin/service auditd stop
#remove old kernels
/bin/package-cleanup –oldkernels –count=1
#clean yum cache
/usr/bin/yum clean all
#force logrotate to shrink logspace and remove old logs as well as truncate logs
/usr/sbin/logrotate -f /etc/logrotate.conf
/bin/rm -f /var/log/*-???????? /var/log/*.gz
/bin/rm -f /var/log/dmesg.old
/bin/rm -rf /var/log/anaconda
/bin/cat /dev/null > /var/log/audit/audit.log
/bin/cat /dev/null > /var/log/wtmp
/bin/cat /dev/null > /var/log/lastlog
/bin/cat /dev/null > /var/log/grubby
#remove udev hardware rules
/bin/rm -f /etc/udev/rules.d/70*
#remove uuid from ifcfg scripts
/bin/sed –i”.bak” ‘/UUID/d’ /etc/sysconfig/network-scripts/ifcfg-eno16777984
#remove SSH host keys
/bin/rm -f /etc/ssh/*key*
#remove root users shell history
/bin/rm -f ~root/.bash_history
unset HISTFILE
#remove root users SSH history
/bin/rm -rf ~root/.ssh/
cat /dev/null > ~/.bash_history
history –c
sys-unconfig
# Check services
systemctl status httpd
systemctl disable httpd
systemctl enable httpd
systemctl list-unit-files | grep httpd
systemctl --failed
# Check services
systemctl status httpd
systemctl disable httpd
systemctl enable httpd
systemctl list-unit-files | grep httpd
systemctl --failed