[SPDK] Re: NVMe Multipath subsystem controller IDs

On 08/04/2021 23:09, 松本周平 wrote:
> Hi Jonathan, Ben,

Hi Matsumoto-san,

> I'm not an expert in this area but supporting multiple SPDK target
> instances is also important to iSCSI.
> I see the value of per-subsystem controller ID range and it is already
> added to Linux target.
>
> But we have little auto test for multiple SPDK target instances.
> Could you enhance test/nvmf/target/multitarget.sh to verify the feature?

To verify the controller ID range has changed, an initiator needs to 
connect to the controller and a specified subsystem. For that, I added a 
test to test/nvmf/target/nvme_cli.sh that extracts the controller ID 
from the output of "nvme id-ctrl".

> And do we have negative side effect if we support per-subsystem controller
> ID range?
Not really AFAIK, the more limited controller ID range means a lower 
limit on the number of simultaneous connections to an individual 
controller for a subsystem but there's typically only one connection anyway.