Monthly Archives: August 2012

Linux automatic (Kickstart) install from a DVD

This assumes you are au fait with the basic workings of Red Hat Kickstart.

Consider the situation where you want to install Linux using your standard configuration in a sales office, but the people there have only basic Windows skills.  The easiest way to do this is with a Kickstart DVD.  This will allow you to do the standard install by sending the DVD to the sales office, tell them to boot off it and then type in one simple command.  You could also use that DVD for getting a new site up and running, or in a disaster-recovery situation.

Copying the CDs/DVD

If you are dealing with Red Hat Enterprise Linux (RHEL) 4 or earlier then you might have them on multiple CDROMs or CDROM ISO files, in which case you’ll have to combine them before continuing.  Considering the example of multiple ISO files:

mount -o loop,ro CDROM1.ISO /mnt ; (cd /mnt ; tar cf - .) | (cd /RHELcombined ; tar xf -) ; umount /mnt
mount -o loop,ro CDROM2.ISO /mnt ; (cd /mnt ; tar cf - .) | (cd /RHELcombined ; tar xf -); umount /mnt

Do that for all of the CDROMs.  When you finish copying the DVD or CDROMs the destination directory (/RHELcombined in the example above) will contain a file called .discinfo, which will look something like this:

Red Hat Enterprise Linux 3

That will be the .discinfo from the last disc you extracted, the 4 in the example above refers to the disc number; you have to replace this with a comma-separated list of all the discs, so 1,2,3,4 in this example.

Adding your own Kickstart configuration file

Next you need to adapt your existing network-based Kickstart, if any, by removing the line referencing the installation media, usually it will be something like this:

nfs --server= --dir=/Kickstart/RHEL3

Replace that line with:


Another field you might want to change is the rootpw.  Normally it would look something like this:

rootpw --iscrypted $1$iCRdXskv$nbxsMQw0BUGi6VgEhaIIN.

For a DVD install it might make sense to remove the ‘–iscrypted’ and put in a clear-text password.  Check the disk space specifications in the Kickstart configuration file to make sure they don’t exceed the space on the server you intend installing.  Copy that file into the root with the name ks.cfg.  Unfortunately it has to be that name, which in turns means you can have only one Kickstart configuration per DVD.

Creating the ISO file

The command line I have below needs two variables:

  • $DstISOfile – the name of the destination file
  • $SrcDir – the name of the directory into which you extracted the CDROMs

Set those two before running the command:

cd $SrcDir ; time mkisofs -J -R -T -o $DstISOfile -b isolinux/isolinux.bin -c isolinux/ -no-emul-boot -boot-load-size 8 -boot-info-table . > /tmp/standardoutput 2>/tmp/erroroutput

A few notes on the command line:

  • I find it’s handy to time how long the command runs.
  • The command’s output is very verbose so I have redirected its stdout to one file and stderr to another (that syntax won’t work in csh/tcsh)
  • It should take about ten minutes to run

Testing and burning

I would recommend you test the ISO image using a virtual machine.  Boot off the ISO image and it will quickly respond with a ‘boot:’ prompt, type in this:

linux ks=cdrom

This will launch the installer which will first wipe out the disk, create the partitions and logical volumes—if any—and finally install the requested packages.  Once you’re satisfied that it works as planned, you can burn ISO image as you would burn an DVD.  You should then find a test server to test the install.  Be warned, there will be no prompts after the one above, your server will be wiped out in less than a minute.  Depending on the speed of the server and its DVD drive Linux will install in about fifteen minutes.