[virt-tools-list] [fedora-virt] Virt Tools Survey: What to do about virt-clone

[Kenneth Armstrong]

a)  I clone guests rather frequently, both at home and at work.  Just
like the others, I mainly do this when I am testing things out on the
cloned image while leaving the original intact.

b)  I was advised (by you I think ;) ) to stay away from virt-clone

c)  I usually use the clone option in virt-manager.  Sometimes I just
manually copy the xml and img files and make changes to the xml as
needed, but I don't do that very often as I use the virt-manager
cloning feature more frequently

d)  Nope, just what I stated above

e)  I would like to be able to sysprep a system, especially if I mean
to deploy a brand new system based on something I have already built

f)  multi step processes don't bother me, as long as it doesn't get
too complicated, mostly for efficient use of time at work

g)  not yet



On Tue, May 10, 2011 at 7:56 AM, Richard W.M. Jones <rjones at redhat.com> wrote:
> I've volunteered for the task of fixing virt-clone[0].  There are a
> number of bugs which need to be addressed.  Unfortunately the current
> virt-clone is broken-by-design since it cannot make changes inside the
> guest.
>
>  [0] http://linux.die.net/man/1/virt-clone
>
> The bugs boil down to what Microsoft calls "sysprepping" the clone,
> which is to say, removing its existing identity, hostname, ssh host
> keys, persistent network rules, host SID and workgroup name (for
> Windows).  It's helpful for Linux guests to remove some of this
> stuff[1] -- it will make the cloning process smoother.  For Windows
> it's absolutely required[2].
>
>  [1] https://rwmj.wordpress.com/2010/09/24/tip-my-procedure-for-cloning-a-fedora-vm/
>  [2] http://technet.microsoft.com/en-us/library/cc721940%28WS.10%29.aspx
>
> All that virt-clone can do now is to copy the guest and make some
> simple changes to the libvirt XML (eg. giving it a new MAC address).
> It doesn't even address the sysprepping problem.
>
> The problem with sysprepping is that it's hard to do, and it's
> different for every operating system.  I've summarized some of the
> techniques below.  Worse than that, for some OSes there are different
> levels of sysprepping that an administrator might want; also see
> below.
>
> So I'd like feedback from "virt-clone next generation" users:
>
> (a) Is cloning guests useful for you or not?  Often or infrequently?
>
> (b) Do you currently use virt-clone to clone guests?
>
> (c) Do you have a homebrew method to clone guests?  What does it do?
>
> (d) Do you use another tool to clone guests?  (And how is it?)
>
> (e) When you clone a guest, do you "sysprep" it or would you like to?
> (Using the term "sysprep" generically here, I mean any sort of
> reinitialization for Linux or Windows guests).
>
> (f) How do you feel about a multi-step process?
>
>  virt-clone -> virt-sysprep -> virt-resize (for example)
>
> (g) Have you had other problems with cloning guests?
>
> (h) What have I missed out in this analysis?  What other features have
> you missed in virt-clone?
>
> Sysprepping Windows
> -------------------
>
> This is a complex, manual process.  We do some steps to automate it in
> RHEV.  It's best to read Microsoft's online documentation at
> [2][3][4].
>
>  [3] http://support.microsoft.com/kb/302577
>  [4] http://blogs.technet.com/b/megand/archive/2005/01/20/357570.aspx
>
> Fedora
> ------
>
> In theory you can just write a file /.unconfigured in the root, and
> Fedora will go through the firstboot process at next boot (it will
> reset timezone, root password, netconfig, keyboard, authentication).
>
> Some admins will *not* want all of these things to be reset, and will
> want either a lesser degree of unconfiguration, or will want to
> control each thing manually.
>
> I'm not totally convinced that this hasn't been broken by systemd
> introduction in Fedora 15.
>
> general Linux
> -------------
>
> See [1].
>
> Rich.
>
> --
> Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
> virt-df lists disk usage of guests without needing to install any
> software inside the virtual machine.  Supports Linux and Windows.
> http://et.redhat.com/~rjones/virt-df/
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