NTP Server : Configure NTP Server (NTPd)
Install NTP
root@xshqs02:~# apt-get install ntp
root@xshqs02:~# vim /etc/ntp.conf
# line 21 : comment out default settings and add NTP Servers for your timezone

# line 51 : add network range you allow to receive time syncing requests from clients


NTP Server : Configure NTP Server (Chrony)
root@xshqs02:~# apt -y install chrony
# line 20 : comment out default settings and add NTP Servers for your timezone

# add to the end : add network range you allow to receive time syncing requests from clients

root@xshqs02:~# systemctl restart chrony
Verify OK

Configure NTP Client

root@XSHQS01:~# vim /etc/systemd/timesyncd.conf
add to the end : set NTP server for your timezone
NTP=192.168.108.128
Tested OK
root@XSHQS01:~# systemctl restart systemd-timesyncd
root@XSHQS01:~# timedatectl timesync-status
Server: 192.168.108.128 (192.168.108.128)
Poll interval: 32
For [su] command restriction, set like follows.
root@localhost:~# vi /etc/pam.d/su # line 15 : uncomment and add a group which is allow to run [su] command auth required pam_wheel.so group=adm # add an user you allowed to run [su] to the group you set above root@localhost:~# usermod -aG adm ubuntu |
RHEL config repository, edit /etc/yum.conf
[main]
cachedir=/var/cache/yum/$basearch/$releasever
keepcache=0
debuglevel=2
logfile=/var/log/yum.log
exactarch=1
obsoletes=1
gpgcheck=1
plugins=1
installonly_limit=3