[ovirt-devel] [ovirt-users] Feature: enhanced OVA support

[Richard W.M. Jones]

On Sun, May 14, 2017 at 04:56:56PM +0300, Arik Hadas wrote:
> Hi everyone,
> 
> We would like to share our plan for extending the currently provided
> support for OVA files with:
> 1. Support for uploading OVA.
> 2. Support for exporting a VM/template as OVA.
> 3. Support for importing OVA that was generated by oVirt (today, we only
> support those that are VMware-compatible).
> 4. Support for downloading OVA.
> 
> This can be found on the feature page
> <http://www.ovirt.org/develop/release-management/features/virt/enhance-import-export-with-ova/>
> .
> 
> Your feedback and cooperation will be highly appreciated.

The plan as stated seems fine, but I have some reservations which I
don't think are answered by the page:

(1) How will oVirt know the difference between an OVA generated
by oVirt and one generated by VMware (or indeed other sources)?
A VMware OVF has an XML comment:

<!--Generated by VMware ESX Server, [...] -->

but not any official metadata that I could see.

(By the way, I don't think importing via virt-v2v vs directly will be
any quicker.  The v2v conversion / device installation takes only a
fraction of the time.  Most of the time is consumed doing the format
conversion from VMDK to qcow2.  However you are correct that when you
know that the source is oVirt/KVM, you should not run virt-v2v.)

(2) I think you're going to have a lot of fun generating OVAs which
work on VMware.  As Yaniv says, the devices aren't the same so you'd
be having to do some virt-v2v -like driver installation / registry
modification.  Plus the OVF file is essentially a VMware data dump
encoded as XML.  OVF isn't a real standard.  I bet there are a million
strange corner cases.  Even writing VMDK files is full of pitfalls.

VMware has a reasonable V2V import tool (actually their P2V tooling is
very decent).  Of course it's proprietary, but then so is their
hypervisor.  Maybe oVirt can drive their tools?

Rich.

-- 
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