BlockDeviceDriver uses iscsi protocol to mount volumes

[Nikita Konovalov]

If Cinder is configured to use the BlockDeviceDriver and the block device is located locally to the host with VM it should be attached directly without iscsi target/initiator used.

However it still uses iscsi on the localhost. It results in high CPU load an low disk performance.

Steps to reproduce:

* Change the backing dirver in cinder.conf to BlockDeviceDriver.
* Add local disks to the list of the device in cinder.conf.
See this doc for config parameters' names. https://wiki.openstack.org/wiki/BlockDeviceDriver#OpenStack_Cinder_configuration
* Restart cinder-volume service where it is set up
* Launch a vm and attach as many volumes to it on the same host as possible.
* Run a disk performance test on host and on VM. The difference will be significant.

[Timur Nurlygayanov (tnurlygayanov)]

Nikita, could you please describe steps to reproduce and version of ISO where we have the bug? It will help to properly track the fix during the release and verify the fix when the issue will be fixed.

[Nikita Konovalov (nkonovalov)]

The bug was introduced somewhere in juno release cycle so all 6.x and 7.x ISOs are affected.

Steps to reproduce:

* Change the backing dirver in cinder.conf to BlockDeviceDriver.
* Add local disks to the list of the device in cinder.conf.
See this doc for config parameters' names. https://wiki.openstack.org/wiki/BlockDeviceDriver#OpenStack_Cinder_configuration
* Restart cinder-volume service where it is set up
* Launch a vm and attach as many volumes to it on the same host as possible.
* Run a disk performance test on host and on VM. The difference will be significant.

[Fuel Devops McRobotson (fuel-devops-robot)]

Reviewed: https://review.fuel-infra.org/10329
Submitter: mos-infra-ci <>
Branch: openstack-ci/fuel-7.0/2015.1.0

Commit: 043ef4a8bbbbd736209c83f604e8a53bacf13e85
Author: Nikita Konovalov <email address hidden>
Date: Wed Aug 12 15:07:48 2015

Fix BlockDeviceDriver for local devices

The check for same host of the volume and connector is brought back
after it was lost during refactorings.

Closes-Bug: #1480916
Change-Id: I2bdb6e27a34c5a362f74b12fcdc0c9ecffde29ef

[Fuel Devops McRobotson (fuel-devops-robot)]

Fix proposed to branch: openstack-ci/fuel-7.0/2015.1.0
Change author: Nikita Konovalov <email address hidden>
Review: https://review.fuel-infra.org/10399

[Fuel Devops McRobotson (fuel-devops-robot)]

Reviewed: https://review.fuel-infra.org/10399
Submitter: mos-infra-ci <>
Branch: openstack-ci/fuel-7.0/2015.1.0

Commit: 23cf8078f9b281fa8f102d4ae269862ea4114709
Author: Nikita Konovalov <email address hidden>
Date: Tue Aug 25 09:47:30 2015

Fix BlockDeviceDrive to match the upstream code

The fix was pruposed to upstream so it will be better to keep the code
similar. This change makes code equal to the one that is proposed to master branch.
See review https://review.openstack.org/#/c/200039/

Change-Id: Ic0a20f5614df6b049d48beb32b5ade01a524fcb3
Closes-Bug: #1480916

[Fuel Devops McRobotson (fuel-devops-robot)]

Fix proposed to branch: openstack-ci/fuel-8.0/liberty
Change author: Nikita Konovalov <email address hidden>
Review: https://review.fuel-infra.org/13327

[Fuel Devops McRobotson (fuel-devops-robot)]

Fix proposed to branch: openstack-ci/fuel-8.0/liberty
Change author: Nikita Konovalov <email address hidden>
Review: https://review.fuel-infra.org/13335

[Fuel Devops McRobotson (fuel-devops-robot)]

Change abandoned by Ivan Kolodyazhny <email address hidden> on branch: openstack-ci/fuel-8.0/liberty
Review: https://review.fuel-infra.org/13335
Reason: It's already synced from stable/liberty

[Fuel Devops McRobotson (fuel-devops-robot)]

Change abandoned by Ivan Kolodyazhny <email address hidden> on branch: openstack-ci/fuel-8.0/liberty
Review: https://review.fuel-infra.org/13327
Reason: It's already synced from stable/liberty

[Denis Meltsaykin (dmeltsaykin)]

Won't fix for 6.x series as they are unsupported and there was no progress on the issue.