[virt-tools-list] [virt-manager] Disk target generation for new machines

[Cole Robinson]

On 07/09/2013 06:18 AM, Martin Kletzander wrote:
> Hi,
> 
> I'm trying to fix one problem in VMM and after several hours, I came to
> a conclusion that I'll ask on a list for hints.  When creating new
> machine, we create a disk without bus/target and thus there is a
> conflict in case user adds one more disk with the default bus.  The
> problem is that the new disk gets generates target like 'vda' (neither
> target nor bus are known for the default disk, so the targets that
> should be skipped contain only '[None, None]').
> 
> I managed to "fix" it simply by the following patch (which should be
> applied anyway, since it fixes one apparent problem itself), but the
> problem with the approach is that the default disk gets generated after
> all the other disks ('vdb' if you add one disk).  Removing all the
> targets is obviously not a choice.
> 

Yeah this stuff is a mess. This stuff was originally made complicated by the
virtinst/virt-manager split so going forward we have an option to clean it up.

virt-manager is also fundamentally lacking an important bit here which is
reordering disks in the UI. There's a couple bugs that this feature will solve
at least.

So this is caused by virt-manager-New VM->customize->addhw->disk ? It's hacky,
but you could pass a value vmmDetails.is_customize_dialog to vmmAddHardware,
and if set, don't generate a target for any added disk device. Then it's just
integrated into the set_defaults fold.

And if the patch below is still valuable, please post it as a top level mail
with reproducer steps because I can't quite tell what it fixes by inspection.

> But when the additional disk gets added, all the data for the default
> disk is already visible in the guest XML.  So I'm wondering where the
> problem is.  Either we should be calling redefine_cached() somewhere to
> get the data back into structures or something.  I can't seem to find
> where the disk gets its 'bus' property set.
> 

bus property is set from Guest.set_defaults.

Thanks,
Cole