nexenta driver doesn't report volume stats

[Aimon Bustardo]

The nexenta driver doesn't implement the get_volume_stats function among possibly others. This means that volume creation will fail at the scheduler with the following:

2013-04-08 23:18:35 ERROR [cinder.scheduler.manager] Failed to schedule_create_volume: No valid host was found.

Need to add this functionality to the driver.

[Aimon Bustardo (aimonb)]

See attached patch.

[Aimon Bustardo (aimonb)]

Fixed patch. I missed a line in last one.

[Aimon Bustardo (aimonb)]

This seems to be a more stable version.. It does not fetch real stats info. But it works.

[Aimon Bustardo (aimonb)]

Question: When I get stats from Nexenta as in my first patch with:

stats = self.nms.volume.get_child_props(FLAGS.nexenta_volume, 'health|size|used|available')

I sometimes get the error:

TypeError: can't multiply sequence by non-int of type 'float'

I suspect its due to the T,G appended in reponse from Nexenta. I logged values of those variable as comes from Nexenta:

2013-04-11 23:08:23 INFO [cinder.volume.drivers.nexenta.volume] Query Nexenta Stats Response: health: ONLINE, size: 3.62T, used: 1.65G, available: 2.67T

What measurement is Cinder expecting? Bytes? MB? GB? Thanks!

[Aimon Bustardo (aimonb)]

OK It appears to be GB. Attaching proper patch.

[John Griffith (john-griffith)]

Hi Aimon,

Thanks for doing most of the work on this and providing the patch. I've modified it slightly and am working on the unit test for it, one thing I was wondering; could you provide some insight as to what the get_child_props() call to Nexenta returns (to use in my Mock)?

I can probably piece it together but it would seem you have that info readily available :)

[John Griffith (john-griffith)]

Aimon,

Just noticed that you're a contributor, had you intended to submit this patch with unit tests? If so feel free to take ownership of the bug, I din't mean to jump in if you were intending to fix it.

[Aimon Bustardo (aimonb)]

Sure I can take it.. Will write the tests and submit.

[Aimon Bustardo (aimonb)]

On Second thought I see you have already done some fo the work. Go ahead and keep it.. child_props returns a dict/hash:

{health: 'ONLINE|OFFLINE|??', size: '<sIze>[G|T]', used: '<sIze>[G|T]', available: '<sIze>[G|T]'}

The most recent patch converts these to GB that Cinder expects. I have a mad workload atm so will appreciate any help you can give adding the missing tests and submitting this.

[Aimon Bustardo (aimonb)]

Note: I have not had anything smaller the G, it may very well return KB also if it gets small enough, The patch accounts for that but no smaller units.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/26869

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/26869
Committed: http://github.com/openstack/cinder/commit/781055bc1f30cebe08848130f3a40764f7f1bb4f
Submitter: Jenkins
Branch: master

commit 781055bc1f30cebe08848130f3a40764f7f1bb4f
Author: John Griffith <email address hidden>
Date: Fri Apr 12 11:11:38 2013 -0600

    Add stats reporting to Nexenta Driver

    Nexenta driver was never updated to report stats.
    This change doesn't include support for backend_name assignment
    via configs, there's some other work that will need to be
    done to enable that.

    Fixes bug: 1166607

    Change-Id: Id9cfff24df8815a67e42393aa18fd41ac1b9e6b3

[Avishay Traeger (avishay-il)]

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nexenta driver doesn't report volume stats" sent on 25/04/2013 7:39:43.

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[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/grizzly
Review: https://review.openstack.org/28206

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/28206
Committed: http://github.com/openstack/cinder/commit/2f72682bc2e8ab653c92b0fe61d50e2f8ee0ccff
Submitter: Jenkins
Branch: stable/grizzly

commit 2f72682bc2e8ab653c92b0fe61d50e2f8ee0ccff
Author: John Griffith <email address hidden>
Date: Fri Apr 12 11:11:38 2013 -0600

    Add stats reporting to Nexenta Driver

    Nexenta driver was never updated to report stats.
    This change doesn't include support for backend_name assignment
    via configs, there's some other work that will need to be
    done to enable that.

    Fixes bug: 1166607

    Change-Id: Id9cfff24df8815a67e42393aa18fd41ac1b9e6b3
    (cherry picked from commit 781055bc1f30cebe08848130f3a40764f7f1bb4f)