Linux sys-unconfig: Reconfigure the System Upon Next Boot

Posted on in Categories , , last updated July 22, 2012

I can use unconfigure command on a previously configured Solaris Unix box and leave it in an unconfigured state. How do I unconfigure CentOS Linux OR RHEL 6.x on HP server. How do I reconfigure the system upon next boot?

You can use sys-unconfig command whoch provides a simple method of reconfiguring a system in a new environment. Upon executing sys-unconfig will halt your system, and run the following configuration programs at boot:

  1. Change the root password.
  2. Reconfigure networking / routing.
  3. Reconfigure time / date / time zone etc.
  4. Reconfigure Keyboard and mapping.
  5. Reconfigure system authentication resources.
  6. Reconfigure system runlevel.
  7. Reconfigure system services.

Type the following command as root user. Warning: do not type the following command on a production server for just testing purpose. The system will go down immediately:
# sys-unconfig
This command will create a file called /.unconfigured. The presence of this file will cause /etc/rc.d/rc.sysinit to run the programs mentioned above. Also, all persistent rules will be deleted from /etc/udev/rules.d/.

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

4 comment

  1. How to do build Server from Clone?

    1. Modify /etc/hosts and /etc/sysconfig/network for new hostname.
    2. Modify /etc/sysconfig/network-scripts/ifcfg-eth*for MAC address and IP address.
    3. Also modify /etc/sysconfig/network-scripts/route-eth*
    4. Modify IP address in sshd_config.
    5. Run # sysctl kernel.hostname new_hostname
    6. Run sys-unconfig and reboot.
    7. Verify bb setup add new hostname on server itself and BBSERVER too.
    8. Verify auto.home, resolv.conf as per environment.
    9. Verify RHEL.repo and update patches as per environment.

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