On Thu, Sep 30, 2021 at 12:53:51PM +0100, Richard W.M. Jones wrote:
On Thu, Sep 30, 2021 at 01:12:39PM +0200, Laszlo Ersek wrote:
> All this requires virt-v2v to parse complete <address> elements from the
> original domain XML, and to generate complete <address> elements in the
> destination domain XML. Is that feasible?
Just to put a bit of flesh on these bones, links to the source:
The input is not always (in fact, hardly ever) full libvirt XML.
It's
input specific to the hypervisor. For VMware it might be:
- the *.vmx file (the real source of truth) (-i vmx)
Here's the virt-v2v code that can parse either a local or remote (over
ssh) *.vmx file into virt-v2v's internal metadata representation:
https://github.com/libguestfs/virt-v2v/blob/master/input/parse_domain_fro...
Libvirt also has a vmx driver, but I decided not to use it because it
just adds an extra translation step and probably loses fidelity in the
process.
In all cases, the *.vmx file is the source of truth for VMware.
- partial libvirt XML generated by libvirt's vpx driver, but
this is
derived from information from VMware APIs and ultimately that comes
from the *.vmx file (-i libvirt -ic esx:// or -ic vpx://)
The libvirt driver:
https://gitlab.com/libvirt/libvirt/-/tree/master/src/esx
I've hacked on this one a little bit in the past, and ... it's complicated.
- the *.ovf file (-i ova)
OVF is a pseudo-standard invented by VMware, but essentially a plot so
they can say they are "standard" when in fact it's just a data dump of
internal VMware structures with no compatibility across software that
generates or consumes OVF.
Here's our OVF parser (for VMware-OVF):
https://github.com/libguestfs/virt-v2v/blob/master/input/OVF.ml
We can also generate OVF, but we generate the RHV-flavour of OVF which
(see above) is not related except that some XML element names overlap.
- nothing at all! (-i disk)
If you give virt-v2v just a disk then it will invent some metadata:
https://github.com/libguestfs/virt-v2v/blob/5adf437bcc00586961d8aa058559f...
Rich.
--
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