Libvirt: defaulting dev bus for block devices sometimes breaks

[Nikola Đipanov]

Libvirt driver would try to decide the device bus (in case it was not
specified or not a valid value) based on the device name. This can fail,
but the possible failure wasn't taken into account.

See bug #1229273 for the stack trace.

[Shree Duth Awasthi (shreeduth-awasthi)]

For unknown device, exception is already being catched in nova/virt/libvirt/blockinfo.py ( Grizzly )

144 else:
145 raise exception.NovaException(
146 _("Unable to determine disk prefix for %s") %
147 disk_bus)

Can you please let us know which version of openstack are you referring to ?

>> This can fail, but the possible failure wasn't taken into account. Can you please let us know which failure scenario are you refering to ? Can you please eloborate.

[Shree Duth Awasthi (shreeduth-awasthi)]

Hi Nikola,

A Gentle reminder.

Please let me know, if my understanding is incorrect.

Thanks.

[Nikola Đipanov (ndipanov)]

>> This can fail, but the possible failure wasn't taken into account. Can you please let us know which failure scenario are you refering to ? Can you please eloborate.

I think that the bug is about - if this exception is raised - the instance will go to error, but there is very little that the user will know about it - so we should add an event in that case or something similar.

[Davanum Srinivas (DIMS) (dims-v)]

This is a really old bug, please reopen if needed since we have moved to newer libvirt etc.