How can I allow an existing paravirtualized instance to boot from a CD-ROM image?
2 Answers
You can't do this with PV. You can always do this with HVM and then switch the vanilla kernel with a PV Xen kernel.
If you are trying to install Debian, Ubuntu, Fedora, CentOs or Gentoo, you can always use xen-tools which will do all the work for you. I believe you also have virt-install but I don't know which distributions can be installed using that.
you can create CD /DVD on nfs or ftp then can boot from cd/dvd or you can use http://convirture.com