Use tap2 instead of tap for Xen disks

[Alvaro Lopez]

Hi.

I am running Xen-4.1.3 + Libvirt-1.0.2 on a Grizzly installation and the machines are not able to view their disk anymore:

     XENBUS: Waiting for devices to initialise: 295s...290s...285s...280s...275s...270s...265s...260s...255s...250s...245s...240s...235s...230s...225s...220s...215s...210s...205s...200s...195s...190s...185s...180s...175s...170s...165s...160s...155s...150s...145s...140s...135s...130s...125s...120s...115s...110s...105s...100s...95s...90s...85s...80s...75s...70s...65s...60s...55s...50s...45s...40s...35s...30s...25s...20s...15s...10s...5s...0s...
    XENBUS: Timeout connecting to device: device/vbd/51712 (local state 1, remote state 1)
    XENBUS: Device not ready: device/vbd/51712

This is because blktap has been substituted by blktap2 [1] so we should use "tap2" for the driver name, instead of "tap". I do not know if this is also true with older (i.e. 4.0) versions of Xen, so at least it should be configurable.

I will submit a patch later today.

[1] http://wiki.xenproject.org/wiki/Blktap2

[Alvaro Lopez (aloga)]

This is related, but not a duplicate of https://bugs.launchpad.net/nova/+bug/1084618

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/32379

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/34529

[Alvaro Lopez (aloga)]

The #3 message was due to a bad bug number in the commit msg.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/32379
Committed: http://github.com/openstack/nova/commit/5c6269a6d0c6fbe13120f9a559fb2fc45542674f
Submitter: Jenkins
Branch: master

commit 5c6269a6d0c6fbe13120f9a559fb2fc45542674f
Author: Alvaro Lopez Garcia <email address hidden>
Date: Fri Jun 7 11:01:16 2013 +0200

    Select disk driver for libvirt+Xen according to the Xen version

    There are two versions of the blktap [1] driver available under Xen.
    blktap1 has been replaced by blktap2 that does not support "tap"
    devices but "tap2", therefore we should use "tap2" devices by default.

    Fixes bug 1188517
    Fixes bug 1084618
    DocImpact

    Change-Id: I8b46885b0909de7cb51fd2d0f6ba2e9bcbf33cc6