Re: [PATCH 6/8] scsi: scsi-multipath: Maintain sdev->access_state

[Hannes Reinecke]

On 3/10/26 12:49, John Garry wrote:
> Now that ALUA is supported, we can maintain sdev->access_state.
>
> However, preferred_path is still not maintained as that that is related
> to transitioning  state and we do not yet support that (for SCSI
> multipath).
There is an issue with the preferred path in general, namely that it 
overlays the ALUA states (ie you can have 'acive/non-optimized' _and_
the preferred path bit set). So it only makes sense for explicit ALUA
as then the preferred path bit gives us an indicator that we might /
should switch paths.

If we restrict ourselves to implicit ALUA (which I'm advocating anyway
for scsi-multipath) the preferred path becomes rather pointless as
we cannot influence path selection at all.

Cheers,

Hannes
--
Dr. Hannes Reinecke                  Kernel Storage Architect
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