Cinder iSCSI configuration lost on target.service start/restart

[Gorka Eguileor]

This bug relates to iSCSI lio helper.
When target.service is started or restarted all lio iSCSI configuration is lost.

How to reproduce it:
Create an instance and attach an iSCSI (with lioadm as helper) volume to it, the instance can see the volume.
Start or Restart target.service on the server serving the volume, the instance loses connectivity.

Output example:
-Expected results:
[root@example ~]# cinder-rtstool get-targets
iqn.2010-10.org.openstack:volume-12e8ca9e-a786-482e-9c80-8d3e9a6cbb42
[root@example ~]# systemctl restart target
[root@example ~]# cinder-rtstool get-targets
iqn.2010-10.org.openstack:volume-12e8ca9e-a786-482e-9c80-8d3e9a6cbb42

- Actual results:
[root@example ~]# cinder-rtstool get-targets
iqn.2010-10.org.openstack:volume-12e8ca9e-a786-482e-9c80-8d3e9a6cbb42
[root@example ~]# systemctl restart target
[root@example ~]# cinder-rtstool get-targets

Additional info:
This bug happens because rtstool is only making changes to configfs and not making these changes as persistent. So when target.service starts/restarts and looks for desired configuration he doesn't find latest Cinder changes and loads whatever configuration was saved, which usually is an empty configuration.

Desired behavior would be for Cinder to make changes as persistent so there's a coordinated access from multiple APIs (target daemon, Cinder, targetcli...).

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/160428

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/160428
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=706878deaaa5acbb8a577942a5a774c58fe16332
Submitter: Jenkins
Branch: master

commit 706878deaaa5acbb8a577942a5a774c58fe16332
Author: Gorka Eguileor <email address hidden>
Date: Mon Mar 2 15:51:07 2015 +0100

    Make lio iSCSI changes persistent to avoid lost

    To avoid losing iSCSI configuration when target.service is
    started/restarted we make persistent any change Cinder makes to the
    configuration.

    This will allow us to coordinate access from multiple rtslib users
    (target daemon, targetcli, cinder...)

    This patch changes rtstool and adds an additional command "save" with
    optional parameter the filename where we want to save current
    configuration. If no parameter is provided it saves to default location
    defined by rtslib.

    Closes-Bug: #1427301
    Change-Id: I74bd09ed16a2e0e584d3e04762aec8cbdf101f6d