Re: [GSoC2016] BlueStore SMR Support

[Ric Wheeler <rwheeler@redhat.com>]

On 03/14/2016 12:42 PM, Shehbaz Jaffer wrote:
> Sorry for the late reply.
>
>>>>> Would that be https://github.com/hgst/libzbc from HGST?
> Thanks Giridhar for the link.
>
> Hi Rick,
>
>> Just keep in mind that different vendors have different behaviors - you will
>> need to tweak it I assume to make it act like the drive you are interested
>> in.
> There is a T10 and T13 standardization for interfaces (ZBC and ZAC
> standard). libzbc also follows these standards. From libzbc README
>
> "libzbc implemention is compliant with the latest drafts of
> the ZBC and ZAC standards defined by INCITS technical committee T10 and
> T13 (respectively)."
>
> I plan to keep the scope of the project such that the allocator will
> interact with the libzbc interface in emulated mode which is T10 and
> T13 standard compliant. Once the allocator works on libzbc emulated
> mode, it can run on disks that support ZBC/ZAC commands. Again from
> README.
>
> "In addition to supporting ZBC and ZAC disks, libzbc also implements an
> emulation mode allowing emulating the behavior of a host-managed zoned
> disks using a regular file or a raw standard block device as backing
> storage."
>
>   Is there any other vendor specific behaviour that I should consider?
>
> Thanks,
> Shehbaz
>
>

I think that following the spec is the right way to go. Last time we did a meet 
up with all of the various SMR vendors, they still had a lot of differences in 
how the devices actually worked though (number of zones, how to reset a zone, etc).

If the spec process works thought, this should all hopefully converge :)

Ric