Bug 1756394 - Add Unity replication support
Summary: Add Unity replication support
Keywords:
Status: CLOSED DEFERRED
Alias: None
Product: Red Hat OpenStack
Classification: Red Hat
Component: openstack-cinder
Version: 16.0 (Train)
Hardware: Unspecified
OS: Unspecified
medium
medium
Target Milestone: beta
: 17.0
Assignee: Alan Bishop
QA Contact: Evelina Shames
RHOS Documentation Team
URL:
Whiteboard:
Depends On:
Blocks: epmosp17features, epmosp17rfe 1718945
TreeView+ depends on / blocked
 
Reported: 2019-09-27 14:18 UTC by arkady kanevsky
Modified: 2022-11-23 10:17 UTC (History)
16 users (show)

Fixed In Version: openstack-cinder-15.0.1-0.20191128040416.ef025a7.el8ost
Doc Type: No Doc Update
Doc Text:
This is a fix to enable partner testing of a currently unsupported feature - cinder replication. I wanted to add this explicitly to be sure it's clear we don't want to release note this one.
Clone Of:
Environment:
Last Closed: 2022-11-23 10:17:48 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
OpenStack gerrit 633451 0 'None' MERGED Unity: Add replication support 2021-02-03 09:58:09 UTC
Red Hat Issue Tracker OSP-2249 0 None None None 2022-11-23 09:34:52 UTC

Description arkady kanevsky 2019-09-27 14:18:01 UTC
Description of problem:
Unity replication finally landed upstream into Train https://review.opendev.org/#/c/633451/
That cannot be backported upstream.

RHOSP13 does support replication already.
So the ask is to pull in Unity driver changes for it. 

Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
1.
2.
3.

Actual results:


Expected results:


Additional info:

Comment 1 arkady kanevsky 2019-09-27 14:33:00 UTC
Testing will be done for Dell EMC eLab team.

Comment 3 arkady kanevsky 2019-10-03 18:23:06 UTC
Given amount of work for backport, lets not do it.
And target it for OSP16.
DellEMC can test it.

Comment 7 Rajini Karthik 2020-02-03 15:44:15 UTC
Luigi
What info do you need? Is this ready for testing?

Comment 8 Alan Bishop 2020-02-03 15:51:18 UTC
Rajini,

The code was on stable/train, and so it's present in any of our OSP-16 releases. The feature is ready for you to test, and I believe the needinfo was to track getting your test results.

Comment 9 Rajini Karthik 2020-02-03 16:08:11 UTC
Thanks alan. We will test

Comment 10 Rajini Karthik 2020-02-03 16:16:25 UTC
Will the certification tests cover Replication?

Comment 11 Gregory Charot 2020-02-03 18:31:40 UTC
This is still TBD, Cinder replication general feature is not currently supported, the certification details will be discussed when we will productise the feature.

Comment 12 arkady kanevsky 2020-02-03 18:38:54 UTC
Greg,
I interpret that as
1. Dell EMC will do its own validation of replication on Unity
2. There is not replication certification for OSP13-16.
3. If we want to list that as a feature for our certified driver we should add it to driver documentation for RHOSP13 and add it to certification documentation. That means 2 new BZs for it that are dependent on this one.

Right?

Comment 13 Gregory Charot 2020-02-03 19:04:55 UTC
(In reply to arkady kanevsky from comment #12)
> Greg,
> I interpret that as
> 1. Dell EMC will do its own validation of replication on Unity
Correct

> 2. There is not replication certification for OSP13-16.
OSP 13 for sure, 16 we will need to check if that's a feature we're willing to fully support during the 16 cycle.

> 3. If we want to list that as a feature for our certified driver we should
> add it to driver documentation for RHOSP13 and add it to certification
> documentation. That means 2 new BZs for it that are dependent on this one.

This feature is driver dependent like Cinder multi attach. In order to productise full support, the general feature (cinder replication) must be supported by RH then the driver itself must support it.

Today Cinder replication is not supported by RH so even if the driver part works, the feature is not supported as RH needs to be able to _reproduce_ and fix any non driver (core) related issue.
Until the general feature is supported the only way to run this in production is to ask for a support exception.

> 
> Right?

Comment 14 Rajini Karthik 2020-02-04 15:25:59 UTC
We have tested the fix.


The image is ready: https://access.redhat.com/containers/#/registry.connect.redhat.com/dellemc/openstack-cinder-volume-dellemc/images/13.0-4-33.

Please refer https://docs.openstack.org/cinder/latest/configuration/block-storage/drivers/dell-emc-unity-driver.html to create a compressed volume.
 
Note
In Unity, only All-Flash pools support compressed volume, for the other type of pools, “‘compression_support’: False” will be returned when getting pool stats.

(overcloud) [heat-admin@elabdir83ctl0 ~]$ cinder get-pools --detail
+-----------------------------+---------------------------------+
| Property                    | Value                           |
+-----------------------------+---------------------------------+
| allocated_capacity_gb       | 0                               |
| compression_support         | True                            |

Comment 15 Rajini Karthik 2020-02-04 15:31:19 UTC
(In reply to Gregory Charot from comment #13)
> (In reply to arkady kanevsky from comment #12)
> > Greg,
> > I interpret that as
> > 1. Dell EMC will do its own validation of replication on Unity
> Correct
>
 
Validation is complete

> > 2. There is not replication certification for OSP13-16.
> OSP 13 for sure, 16 we will need to check if that's a feature we're willing
> to fully support during the 16 cycle.
> 

Can we update the new container catalog (and the certs page if applicable) to list this as a feature for the Unity Plugin?
And any other documentation for Unity in the RH docs.

> > 3. If we want to list that as a feature for our certified driver we should
> > add it to driver documentation for RHOSP13 and add it to certification
> > documentation. That means 2 new BZs for it that are dependent on this one.
> 
> This feature is driver dependent like Cinder multi attach. In order to
> productise full support, the general feature (cinder replication) must be
> supported by RH then the driver itself must support it.
> 
> Today Cinder replication is not supported by RH so even if the driver part
> works, the feature is not supported as RH needs to be able to _reproduce_
> and fix any non driver (core) related issue.
> Until the general feature is supported the only way to run this in
> production is to ask for a support exception.
> 
> > 
> > Right?

Comment 16 Rajini Karthik 2020-02-04 15:35:38 UTC
Ignore the two recent comments, they are meant for bug 1779744. For the compression feature. Sorry

Comment 18 Paul Grist 2020-02-07 00:31:00 UTC
PG>> Hi Arkady,

> Greg,
> I interpret that as
> 1. Dell EMC will do its own validation of replication on Unity
Correct

> 2. There is not replication certification for OSP13-16.
OSP 13 for sure, 16 we will need to check if that's a feature we're willing to fully support during the 16 cycle.

PG>>  As Greg indicated there is no CERT test because it's not a supported feature yet and based on what we know, would be a post-16.0 consideration due the the post-queens failback and other patches that landed after the initial upstream delivery of the core replication feature.

> 3. If we want to list that as a feature for our certified driver we should
> add it to driver documentation for RHOSP13 and add it to certification
> documentation. That means 2 new BZs for it that are dependent on this one.

This feature is driver dependent like Cinder multi attach. In order to productise full support, the general feature (cinder replication) must be supported by RH then the driver itself must support it.

Today Cinder replication is not supported by RH so even if the driver part works, the feature is not supported as RH needs to be able to _reproduce_ and fix any non driver (core) related issue.
Until the general feature is supported the only way to run this in production is to ask for a support exception.

PG>>  In addition to Greg's reply, I wanted to reply here after sending a recent email on the topic.  We can definitely discuss how to bring this feature to customers, it will start with this fix giving Dell the ability to test. We can discuss directly, but we would need joint access to at least one Dell backend that wants to deliver cinder replication and to discuss testing until we have it as a supported feature in a future release and certification test/plan for it.

Comment 19 arkady kanevsky 2020-02-07 16:27:03 UTC
Paul,
so how do we want to position the message for the field and the customers?
Do we go support case/support exception route?
Can we handle it for OSP13 and OSP16?
Will OSP16 fully support replications starting from OSP16.xxx?

Thanks,
Arkady

Comment 20 arkady kanevsky 2020-02-07 16:33:07 UTC
In addition,
does OSP16 certification covers replication? If not when will it be extended for it?
We can do validation of replication for Unity.
But we will need to line up which OSP version and which z-stream for it.

Thanks,
Arkady

Comment 21 Gregory Charot 2020-02-07 17:02:15 UTC
No plan for 13, missing some key features.

16 we need to find a way to QE the general feature as well as replicating and fixing non driver related bugs. Our QE does not currently have access to HW to do so. Until then the only path is support exception.

There is no certification plans until we solve the above. This is really a matter of HW for testing and verifying bugs, we can eventually TP the feature as a mean to position the feature.

Comment 22 arkady kanevsky 2020-02-07 18:57:00 UTC
So the only way to deliver replication to customer is thru support exception?
That sucks.

If we gave you access to HW will RH be able to state that as supported feature for that HW?

Comment 23 Gregory Charot 2020-02-11 10:22:46 UTC
RH has no industrial/automated way to test it due to lack of hardware so yes SE only for now. Even if the feature was marked tech preview, customers would need a SE for running it in production.

If our QE/Eng can have access to HW that supports replication then it would indeed greatly help productising the feature. Partners still need to go through certification as a mean to advertise that their backend is certified for this specific feature as well as their willingness to support it.

Comment 24 Lon Hohberger 2020-02-13 11:40:33 UTC
According to our records, this should be resolved by openstack-cinder-15.0.2-0.20200123220928.900f769.el8ost.  This build is available now.

Comment 25 Gregory Charot 2020-03-25 11:22:35 UTC
Cinder replication is not supported in OSP16, moving to 17.

Comment 27 arkady kanevsky 2020-09-11 18:52:09 UTC
Why 17 and not 16.2?

Comment 28 Alan Bishop 2020-09-11 19:12:46 UTC
Greg may have more info, but it's mainly because 16.2 will still be based on Train where we don't support cinder replication.

Comment 36 Gregory Charot 2022-11-23 10:17:48 UTC
No plan to support cinder replication in the near futur, closing deferred to avoid possible support confusion.


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