How to configure the NTP in AIX and LINUX servers?

How to configure the NTP in AIX and LINUX ?

A) STEPS

 For RHEL pls follow the below steps:

1. stop the NTP service

#service ntpd stop

2. Make a copy of the file /etc/ntp.conf

#cp /etc/ntp.conf /etc/ntp.conf_bak

3. Edit the file /etc/ntp.conf with the following entries:

    server <IP_address of the NTP server>

server <IP_address of the NTP server>

        driftfile /var/lib/ntp/drift 

4. Create the /var/lib/ntp directory if it’s not exist and ensure /var/lib/ntp has correct ownership and      permissions

           #mkdir /var/lib/ntp

          ( dwxr-xr-x 2 ntp ntp 4096 Mar  2 11:09  )

5. Create the file /var/lib/ntp/drift with the following entry:

         0.0

6. After creating the drift file, ensure that it has the right ownership and permissions:

        -rw-r--r-- 1 ntp ntp 6 Mar  2 11:09 drift

7.  After restarting the ntpd service, ensure that spurious messages in the /var/log/messages file are no longer reported:

           can't open /etc/ntp.drift.TEMP: Permission denied

8. Bounce NTP service.

    # service ntpd restart 

9. Status checking

   # ntpq

   ntpq> peers

10. Make sure the ntp starts automatically start at the boot time 

   # chkconfig ntpd on 

For AIX please follow the below steps:

1. Stop the ntp services
#stopsrc –s xntpd

2. Sync the time with ntp, login as root, type
      #ntpdate  <ip_address of the NTP server>

3. Make a copy of the file /etc/ntp.conf
#cp /etc/ntp.conf /etc/ntp.conf_bak

4. Edit file /etc/ntp.conf and append
    server <ip_address of the NTP server>
    driftfile /var/lib/ntp/drift  
    tracefile /etc/ntp.trace

5. Create the /var/lib/ntp directory and ensure /var/lib/ntp has correct ownership and permissions
           #mkdir /var/lib/ntp
( dwxr-xr-x 2 ntp ntp 4096 Mar  2 11:09  )

6. Create the file /var/lib/ntp/drift with the following entry:
         0.0

7. After creating the drift file, ensure that it has the right ownership and permissions:
-rw-r--r-- 1 ntp ntp 6 Mar  2 11:09 drift  

8. Start the NTP sercice
#startsrc –s xntpd

9. Take backup and uncomment xntpd from /etc/rc.tcpip. so it will start on a reboot.
#cp –p /etc/rc.tcpip /etc/rc.tcpip_bak 
        #vi /etc/rc.tcpip
        Uncomment the following line
Start /usr/sbin/xntpd “$src-running”  

10. Verify that the server is synched.
       #lssrc -ls xntpd

B) VALIDATION:

ntpdate –q <ntpserver> should not show the time difference more than 1 sec.

C) ROLLBACK

Replace all the configuration files that you have modified with the backup copies taken at the time of implementation .

How to set the standard shell prompt in aix servers?

How to set the standard shell prompt in aix servers?


1. Pre-work:

          Make sure to take the copy of the /etc/profile file using the below command.
             cp -p /etc/profile /etc/profile_old

2. Steps:

Append the following lines to the file /etc/profile to change the format of the shell prompt.
         PS1=`whoami`@`hostname –s`: '$PWD>'
         export PS1


For example you login as a root to the server test_server and you are in /etc the prompt look like the following:   Syntax: username@servername:presentworkingdirectory>    
              root@test_server:/etc>


3. Validation:
                Open a new login session and you should see the change in shell prompt.

4. Roll back:
               Remove the entry that you have added to the file “/etc/profile”