Direct mode exports a physical NVMe device, specified by
domain:bus:device.function, over NVMe-oF. Virtual mode can export any
type of device, specified using the 'Namespace' directive, over NVME-
oF.


On Tue, 2017-02-28 at 20:08 +0530, Ankur Srivastava wrote:
> Thanks Thomas for the work around I have made the subsystem2 as
> Virtual Mode, but still the error persists.  
> Error I am getting is related to the subsystem1.
> 
> Modified conf.in
> -------------------------------
> # Direct controller
> [Subsystem1]
>   NQN nqn.2016-06.io.spdk:cnode1
>   Core 0
>   Mode Direct
>   Listen RDMA 192.168.25.3:4420
>   Host nqn.2016-06.io.spdk:init
>   NVMe 0000:06:00.0

Here's the error you are getting:

conf.c: 565:spdk_nvmf_parse_subsystem: ***ERROR*** Could not find NVMe
controller for Subsystem1

If you look at Subsystem1, it's in Direct mode and trying to export the
NVMe device at 0000:06:00.0. You explained earlier that you do not have
an NVMe device attached, so the error is telling you that it can't find
the device at that location. Instead, either delete Subsystem1 if you
don't need it, or make Subsystem1 a virtual subsystem and add
namespaces too it like you did for Subsystem2.

> 
> # Multiple subsystems are allowed.
> # Virtual controller
> [Subsystem2]
>   NQN nqn.2016-06.io.spdk:cnode2
>   Core 0
>   Mode Virtual
>   Listen RDMA 192.168.25.31:4420
>   Host nqn.2016-06.io.spdk:init
>   SN SPDK00000000000001
>   Namespace Malloc0
>   Namespace Malloc1
>