[Libguestfs] [PATCH] v2v: remove MAC address related information

[Tomáš Golembiovský]

On Tue, 27 Feb 2018 13:43:59 +0100
Fabien Dupont <fdupont at redhat.com> wrote:

> We can still find them and run the sysprep, but I have
> the feeling that it would be more logical if virt-v2v did the sysprep when
> target is oVirt / RHV.

This is trickier than you think. For LVM volumes somebody (VDSM) has to
lock and prepare the disks for you first and there is no external API to
do that AFAIK.

    Tomas


> 
> On 27 February 2018 at 13:34, Richard W.M. Jones <rjones at redhat.com> wrote:
> 
> > On Tue, Feb 27, 2018 at 12:53:08PM +0100, Pino Toscano wrote:  
> > > On Tuesday, 27 February 2018 12:35:36 CET Tomáš Golembiovský wrote:  
> > > > Remove ties to MAC address because it is likely to change.  
> > >
> > > v2v tries to preserve the MAC address of network interfaces; few months
> > > ago we did a fix regarding this:
> > > https://bugzilla.redhat.com/show_bug.cgi?id=1506572
> > >
> > > The approach of this patch is IMHO not good, since it removes the MAC
> > > address from the network-scripts, but still the rest of v2v will try
> > > to preserve the MAC addresses.  
> >
> > We preserve the MAC address in metadata.  On the other hand AIUI this
> > patch only removes the association in the ifcfg files and the guest
> > will reassociate it when it boots (albeit it might then mix up the
> > ethernet interfaces so that's not good).
> >
> > There's IMHO a bigger problem which is not being addressed:
> >
> > https://bugzilla.redhat.com/show_bug.cgi?id=1318922
> >  
> > > What's the reason behind this patch?  
> >
> > There's a bit of background which is missing.  Tomáš and I had some
> > discussions (privately, unfortunately) with the ManageIQ developers
> > who are integrating virt-v2v into MIQ/CloudForms.  Their existing
> > software runs a separate virt-sysprep step on guests after they have
> > been converted by virt-v2v.  They disable all sysprep the operations
> > except for just a couple, including ‘net-hwaddr’, so the effect is
> > roughly the same as this patch.
> >
> > The question was raised why they need to do that as a separate step
> > and why virt-v2v doesn't do it.  And indeed there was some discussion
> > about whether or not converted guests need a new MAC address -- it's
> > at best unclear -- it is thought that VMware might reuse MAC addresses
> > which have "left" the hypervisor, although no one knows if that's
> > really true or not.
> >
> > I don't have much opinion on this.  Maybe it's best for CFME to
> > continue to run virt-sysprep as a separate step.
> >
> > Rich.
> >
> > --
> > Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~
> > rjones
> > Read my programming and virtualization blog: http://rwmj.wordpress.com
> > libguestfs lets you edit virtual machines.  Supports shell scripting,
> > bindings from many languages.  http://libguestfs.org
> >  
> 
> 
> 
> -- 
> 
> *Fabien Dupont*
> 
> PRINCIPAL SOFTWARE ENGINEER
> 
> Red Hat - Solutions Engineering
> 
> fabien at redhat.com     M: +33 (0) 662 784 971 <+33662784971>
> 
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-- 
Tomáš Golembiovský <tgolembi at redhat.com>