[Libguestfs] Why libguestfs guest exist exceptionally?

[Richard W.M. Jones]

On Mon, Sep 29, 2014 at 04:00:38PM +0800, Zhi Yong Wu wrote:
> On Mon, Sep 29, 2014 at 1:41 AM, Richard W.M. Jones <rjones at redhat.com> wrote:
> > On Mon, Sep 29, 2014 at 01:35:08AM +0800, Zhi Yong Wu wrote:
> >> On Mon, Sep 29, 2014 at 1:27 AM, Richard W.M. Jones <rjones at redhat.com> wrote:
> >> > User-Mode Linux is also a possibility.  Slow but consistent
> >> Slow is a big concern...
> >
> > There are some measurements here:
> >
> > http://rwmj.wordpress.com/2013/08/14/performance-of-user-mode-linux-as-a-libguestfs-backend/
> What do you think that it is good to backport UML support to 1.20?

Difficult.

I think it would be easier to forward-port the 'oldlinux' branch to
libguestfs 1.24 or 1.26.  However that is still not trivial, as
in particular this patch touches a lot of code:

  https://github.com/libguestfs/libguestfs/commit/2d836027a0a273dbcafa4216f8ab554063d71bf3

A third alternative would be to use an upstream qemu & kernel on top
of RHEL 5:

  http://libguestfs.org/guestfs-faq.1.html#how-can-i-compile-and-install-libguestfs-if-my-distro-doesnt-have-new-enough-qemu-supermin-kernel

I think this third approach may be easiest of all, but will still
require you to carefully fix any porting problems in libguestfs where
we use newer (eg) glibc features than are found in RHEL 5.

(Even easier is to move to RHEL 6 or 7)

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-p2v converts physical machines to virtual machines.  Boot with a
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