Thank you Gorka for your inputs. -----Original Message----- From: Gorka Eguileor <geguileo@redhat.com> Sent: Monday, May 22, 2023 9:53 PM To: Souza, Nahim <Nahim.Souza@netapp.com> Cc: openstack-discuss@lists.openstack.org Subject: Re: [cinder][dev] Add support in driver - Active/Active High Availability On 15/05, Souza, Nahim wrote:

Hi, Raghavendra,

Just sharing my experience, I started working on A/A support for NetApp NFS driver, and I followed the same steps you summarized. Besides that, I think the effort is to understand/test if any of the driver features might break in the A/A environment.

If anyone knows about anything else we should test, I would be happy to know too.

Regards, Nahim Souza.

Hi, I see that there is no mention of deploying and configuring the DLM, which is necessary for the critical sections between different hosts. For reference, most drivers require code changes. A very common location were drivers need code changes is when creating the host entities in the storage array. I see that the 3PAR driver has already changed that lock to use the DLM locks [1]. If a driver doesn't support replication then there is no need to split the failover_host method. Cheers, Gorka. [1]: https://github.com/openstack/cinder/blob/7bca35c935cf8566bcf9e4874be78174cb0...

From: U T, Raghavendra <raghavendra-uddhav.tilay@hpe.com> Sent: Monday, May 8, 2023 09:18 To: openstack-discuss@lists.openstack.org Subject: [cinder][dev] Add support in driver - Active/Active High Availability

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Hi,

We wish to add Active/Active High Availability to: 1] HPE 3par driver - cinder/cinder/volume/drivers/hpe/hpe_3par_common.py 2] Nimble driver - cinder/cinder/volume/drivers/hpe/nimble.py

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Summary of steps: 1] In driver code, set SUPPORTS_ACTIVE_ACTIVE = True 2] Split the method failover_host() into two methods: failover() and failover_completed() 3] In cinder.conf, specify cluster name in [DEFAULT] section cluster = <cluster_name> 4] Configure atleast two nodes in HA and perform testing

Is this sufficient or anything else required ?

Note: For Nimble driver, replication feature is not yet added. So can the above step 2 be skipped?

Appreciate any suggestions / pointers.

Regards, Raghavendra Tilay.