On Fri, May 4, 2018, 21:09 Walker, Benjamin <benjamin.walker(a)intel.com>
wrote:

> On Fri, 2018-05-04 at 17:56 +0000, Andrey Kuzmin wrote:
> > Thanks for the quick turnaround, Daniel.
> >
> > On Fri, May 4, 2018, 20:48 Verkamp, Daniel <daniel.verkamp(a)intel.com>
> wrote:
> > > Hi Andrey,
> > >
> > > Do you mean on the host (initiator) side, bdev/nvme?  When you are
> > > connecting to a NVMe-oF target with the NVMe bdev (either via the
> [Nvme]
> > > configuration file section or the construct_nvme_bdev RPC method), you
> are
> > > specifying the address to a subsystem, and all namespaces in that
> subsystem
> > > will be exposed as bdevs.  There is currently no way to specify just a
> > > single namespace within the subsystem, but we could probably add this
> if
> > > there is a reasonable use case that requires it.
> >
> > I don't think it as strong as required, but the case that has triggered
> my
> > question above was trying to run bdevperf with its target device
> specification
> > against a specific namespace at thee nvmf target.
> >
> > As is (with effectively just the controller specified), it actually runs
> > prerry well, but I assume it does so against all namespaces the target
> exports
> > via the specified subsystem.
>
> When you connect to a controller with the NVMe-oF host, it will create a
> separate bdev for each namespace automatically. If you do something like
> this:
>
> [Nvme]
>   TransportID "trtype:RDMA <stuff>" Nvme0
>
> Then it will create one bdev per namespace with the names Nvme0n1,
> Nvme0n2, etc.
>
> However, when you go to run bdevperf, there isn't actually a way to say to
> just
> run against one of those namespaces.


Exactly.

That's probably a reasonable addition to
> the tool.
>
> (Also, we should consider promoting the tool from a test tool in test/bdev
> to an
> example in examples/bdev.)
>

I have indeed found it pretty useful for testng bdevs.

Regards,
Andrey

>
> >
> > Regards,
> > Andrey
> > > If you are talking about the target side, you can configure namespaces
> to
> > > have a particular ID using the optional second parameter to the
> Namespace
> > > line in the [SubsystemN] config sections, or via the optional
> namespace.nsid
> > > parameter to the nvmf_subsystem_add_ns RPC method.
> > >
> > > Thanks,
> > > -- Daniel
> > >
> > > > -----Original Message-----
> > > > From: SPDK [mailto:spdk-bounces(a)lists.01.org] On Behalf Of Andrey
> Kuzmin
> > > > Sent: Friday, May 4, 2018 10:35 AM
> > > > To: Storage Performance Development Kit <spdk(a)lists.01.org>
> > > > Subject: [SPDK] Nvmf target namespace specification
> > > >
> > > > Spdk nvmf docs suggest nvmf targets to be specified via
> > > > traddr/addrfam/traddr/trsvcid tuple. Is there any way to specify the
> > > > target controller namespace as well?
> > > >
> > > > Regards,
> > > > Andrey
> > > > _______________________________________________
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> >
> > --
> > Regards,
> > Andrey
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-- 

Regards,
Andrey