Ensure that an emergency boot disk is ready to <quote>rescue</quote> the computer if the computer becomes unusable (un-bootable).If you do not already have a boot device, you can create one.In order for the procedure below to work, you need to jump ahead to BLFS and install <userinput>xorriso</userinput> from the <ulink url="&blfs-book;multimedia/libisoburn.html"> libisoburn</ulink> package.