[CentOS] CentOS on Xen question (Xen Hosting)

[Josh Kelley]

On 12/1/05, Leonard Isham <leonard.isham at gmail.com> wrote:
> With everything I've read and researched, prior to this, I've come to
> the conclusion that this would take a considerable amount of time and
> effort.  The resulting installed system would only vaguely resemble
> CentOS on the surface.  Would require a non-standard, most likely self
> created and maintained, repository for yum updates.
>
> IIRC this would require patching and recompiling the kernel, newer gcc
> and recompiling a significant number of other binaries...

Actually, I was able to get CentOS running under Xen (as host and
guest) without too much effort.  Unfortunately, I didn't take very
good notes...  No custom repository or newer gcc or other recompiling
is needed.  A patched kernel is needed, but Xen automates that for
you; see Xen's docs for details.

Xen's web site provides a binary download of Xen 2.0.7, which works
without any problems, although their precompiled kernel (based off of
a stock 2.6.x kernel) contains relatively few modules.  You can also
recompile 2.0.7 from source to add kernel modules.  Getting Xen 2.x to
work with CentOS's customized kernel, or getting Fedora's newer
version of Xen to work, could be quite a bit more effort.

Since you haven't updated glibc, you'll want to mv /lib/tls
/lib/tls.disabled on both host and guest OSes to improve performance. 
Installing the guest OS can be a bit trickier; you can do a CD-based
install (reboot the host off of the CD then install CentOS to an blank
partition that will be used as the guest), or you can use rpmstrap or
yum --installroot.  See
http://mark.foster.cc/wiki/index.php/Centos-4_on_Xen for details on
the latter two options.

Feel free to contact me if you have any more questions.  Hope this helps.

Josh Kelley