Change in vdsm[master]: fileSD: enable mailbox on file domains

danken at redhat.com danken at redhat.com
Mon Apr 7 21:34:49 UTC 2014


Dan Kenigsberg has posted comments on this change.

Change subject: fileSD: enable mailbox on file domains
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Patch Set 2:

(3 comments)

I do not have hard numbers, only rumors, but according to them, the mailbox eats a lot of io and cpu. Barak, do you have the figures?

http://gerrit.ovirt.org/#/c/26414/2//COMMIT_MSG
Commit Message:

Line 9: Since we now support mixed-type storage pools (block and file) we
Line 10: must enable the mailbox on file domains in order to satisfy the
Line 11: extension requests needed by block domains.
Line 12: On file domains the inbox and outbox files were prepared empty so
Line 13: we also need to extend them to the proper size as soon as possible:
> We really don't want to diverge. Sadly the inbox/outbox files were previous
Ok, so the diversion is required in order to upgrade pre-existing file domains. Have you considered using the upgrade mechanism for that (I shudder of the thought, as I recall how fragile it is).

Please add a sentence to this commit message, stating that we create the mailbox in the proper size for new domains.

BTW, fileSD._prepareMetadata first create the inbox/outbox in zero length, and only later sets the proper size.
Line 14: 
Line 15: * on SPM start
Line 16: * on master migration
Line 17: 


Line 12: On file domains the inbox and outbox files were prepared empty so
Line 13: we also need to extend them to the proper size as soon as possible:
Line 14: 
Line 15: * on SPM start
Line 16: * on master migration
Why is it required on master migrate (and not on, say, reconstruct master)? the mailbox is going to be used before SPM is started on the new master, anyway.
Line 17: 
Line 18: Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1083476
Line 19: Change-Id: Iba8036e33ed8718d05e9d83cad1d63949794f067


http://gerrit.ovirt.org/#/c/26414/2/vdsm/storage/sp.py
File vdsm/storage/sp.py:

Line 301
Line 302
Line 303
Line 304
Line 305
> It totally makes sense to disable it for local storage domains. If we want 
If the host cannot see all domains it should not be selected spm...

Alternatively to this complexity, Engine can explicitly ask to enable the mailbox on spm start or domain activation.


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Gerrit-MessageType: comment
Gerrit-Change-Id: Iba8036e33ed8718d05e9d83cad1d63949794f067
Gerrit-PatchSet: 2
Gerrit-Project: vdsm
Gerrit-Branch: master
Gerrit-Owner: Federico Simoncelli <fsimonce at redhat.com>
Gerrit-Reviewer: Allon Mureinik <amureini at redhat.com>
Gerrit-Reviewer: Barak Azulay <bazulay at redhat.com>
Gerrit-Reviewer: Dan Kenigsberg <danken at redhat.com>
Gerrit-Reviewer: Federico Simoncelli <fsimonce at redhat.com>
Gerrit-Reviewer: Nir Soffer <nsoffer at redhat.com>
Gerrit-Reviewer: Tal Nisan <tnisan at redhat.com>
Gerrit-Reviewer: automation at ovirt.org
Gerrit-Reviewer: oVirt Jenkins CI Server
Gerrit-HasComments: Yes


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