XenServer 6.5 iSCSI bug

[Bob Ball]

There is a bug when connecting to Cinder volumes over iSCSI with XenAPI where a tapdisk is not correctly spawned. This has been fixed in https://github.com/xapi-project/sm/commit/7a8a158493d03ceeb31bc8a43b7f213e74420bf0 however, users of XenServer 6.5 need a workaround in Nova.

The impact of this is that, without the fix, XAPI is expecting a tapdisk to be spawned, but the Storage Manager does not spawn one. As such, the VM will not be able to connect to this Cinder volume.

This is being tracked in Nova as https://bugs.launchpad.net/nova/+bug/1502929, but we need a fix for users of the Mirantis OpenStack fuel plugin for XenServer.

A formal hotfix will be released as XS65ESP1013, so we either need to (probably in order of preference):

1) Verify that XS65ESP1013 is installed and if not, raise an error during setup (or perform step #2)

2) Apply a patch manually to /opt/xensource/sm/LUNperVDI.py in dom0 equivalent to the fix from XS65ESP1013.
 index 9a86430..2ef9edd 100755 (executable)
--- a/drivers/LUNperVDI.py
+++ b/drivers/LUNperVDI.py
@@ -55,6 +55,7 @@ class RAWVDI(VDI.VDI):
         sm_config = util.default(self, "sm_config", lambda: {})
         sm_config['LUNid'] = str(self.LUNid)
         sm_config['SCSIid'] = self.SCSIid
+ sm_config['backend-kind'] = 'vbd'
         self.sm_config = sm_config

     def introduce(self, sr_uuid, vdi_uuid):

3) Manually patch compute nodes with https://review.openstack.org/#/c/231103/4/nova/virt/xenapi/volume_utils.py

[Hua Zhihao (huazhihao)]

Will check if XS65ESP1013 installed or raise an exception. https://review.openstack.org/#/c/244467/

[Hua Zhihao (huazhihao)]

https://review.openstack.org/#/c/241126/