On 1/31/2013 10:40 AM, Daniel P. Berrange wrote:
On Thu, Jan 31, 2013 at 10:35:17AM -0800, Michael Rodrigues wrote:
Hi Daniel,
I thought migration might be the reason, but I'm still not seeing the behavior you describe with regards to pausing. I saw the following behavior:
1. Created VM on node 1 2. Started VM on node 1 3. Migrated VM to node 2, node 1 is now shutdown, node 2 is running 4. I paused node 2 5. I started node 1, no error 6. Paused node 1 7. Unpaused node 2, no err
I thought maybe the original VM had to be paused first, so I tried that as well:
1. Created VM on node 1 2. Started VM on node 1 3. Migrated to node 2, node 1 is now shutdown, node 2 is running 4. I shutdown node 2 instead of pausing 5. I started node 1 6. I paused node 1 7. Started node 2 8. Paused node 2 9. Started node 1 Hmm, that isn't supposed to be possible. When you paused node 1 in step 6, it was supposed to record the lease version number. When you resume in step 9, the version number should mis-match due to step 7, and thus sandlock ought to have caused an error at step 9. If that didn't happen, then I believe we have a bug Should I file a report? I'm not really a developer but I can provide whatever information is necessary for a proper report. I don't have RHEL or a bugzilla account.
So sanlock is preventing both from running concurrently, but it seems to contradict your statement: "Even if you now pause the VM on node 2, and try to resume node 1, sanlock will still prevent node 1 from running again. It tracks a lock "version" number. The key is that once the original VM is paused, if any other VM runs on that disk, the orignal VM is never allowed to be unpaused again." Daniel
-- Michael Rodrigues Interim Help Desk Manager Gevirtz Graduate School of Education Education Building 4203 (805) 893-8031 help@education.ucsb.edu