Server

vi /etc/named.conf filter-aaaa-on-v4 yes;   named-checkconf /etc/named.conf   vi /etc/sysconfig/named OPTIONS="-4"   systemctl restart named-chroot systemctl status named-chroot

yum install -y lm_sensors sensors-detect sensors watch sensors\

du -msh /var/crash/* rm  /var/crash/????

ps aux | grep updatedb killall updatedb   ls -alh /var/lib/mlocate/ -rw-r----- 1 root slocate 30G mlocate.db.xxxxxx rm -f /var/lib/mlocate/mlocate.db.xxxxxx   ll /etc/cron.daily/mlocate mkdir /etc/cron.daily/out mv /etc/cron.daily/mlocate /etc/cron.daily/out    

  # cd  # wget https://caucho.com/download/rpm-6.8/4.0.63/x86_64/resin-4.0.63-1.x86_64.rpm # rpm -ivh resin-pro-4.0.63-1.x86_64.rpm   # systemctl daemon-reload   # systemctl enable resin.service  resin.service is not a native service, redirecting to systemd-sysv-install. Executing: /usr/lib/systemd/systemd-sysv-install enable resin Failed to execute /usr/lib/systemd/systemd-sysv-install:    # yum install chkconfig -y # systemctl enable resin.service  resin.service is not a native service, redirecting to systemd-sysv-install. […]

split -b 1GB test.log   < test.log head -n $(cat test.log | grep -m1 -n "2021-07-11" -a | cut -d: -f1) | tail -n +$(cat test.log | grep -m1 -n "2021-07-10" -a | cut -d: -f1) > test.log.20210710   awk 'NR >= 10 && NR <= 100' test.log >new.log.100      

systemctl stop mariadb   mv /var/lib/mysql/ibdata* /backup/ mv /var/lib/mysql/ib_logfile* /backup/   systemctl start mariadb  

rsync -avR --relative --address=192.168.1.42 192.168.1.46::all/test/db/./install/test.txt /backup install/ install/test.txt   Result [192.168.1.46] /test/db/./install/test.txt   [192.168.1.42] /backup/install/test.txt      

yum install autossh -y   autossh -M 0 -o ServerAliveInterval=30 -p22 -L 33061:127.0.0.1:3306 -N test@remote.com     

systemctl status default.target   # to switch runlevels instantly systemctl isolate graphical.target systemctl isolate multi-user.target   ll /etc/systemd/system/default.target   #runlevel 3 ln -sf /lib/systemd/system/multi-user.target /etc/systemd/system/default.target   #runlevel 5 ln -sf /lib/systemd/system/graphical.target /etc/systemd/system/default.target