Re: [Qemu-devel] [RFC PATCH 0/2] GlusterFS support in QEMU - v2

[Stefan Hajnoczi]

On Mon, Jul 23, 2012 at 9:50 AM, Bharata B Rao
<address@hidden> wrote:
> On Sun, Jul 22, 2012 at 03:42:28PM +0100, Stefan Hajnoczi wrote:
>> On Sat, Jul 21, 2012 at 9:29 AM, Bharata B Rao
>> <address@hidden> wrote:
>> > -drive file=gluster:address@hidden:volname:image
>> >
>> > - Here 'gluster' is the protocol.
>> > - 'address@hidden' specifies the server where the volume file 
>> > specification for
>> >   the given volume resides. 'port' is the port number on which gluster
>> >   management daemon (glusterd) is listening. This is optional and if not
>> >   specified, QEMU will send 0 which will make libgfapi to use the default
>> >   port.
>>
>> 'address@hidden' is weird notation.  Normally it is 'server:port' (e.g.
>> URLs).  Can you change it?
>
> I don't like but, but settled for it since port was optional and : was
> being used as separator here.
>
>>
>> What about the other transports supported by libgfapi: UNIX domain
>> sockets and RDMA?  My reading of glfs.h is that there are 3 connection
>> options:
>> 1. 'transport': 'socket' (default), 'unix', 'rdma'
>> 2. 'host': server hostname for 'socket', path to UNIX domain socket
>> for 'unix', or something else for 'rdma'
>> 3. 'port': TCP port when 'socket' is used.  Ignored otherwise.
>>
>> Unfortunately QEMU block drivers cannot take custom options yet.  That
>> would make it possible to cleanly map these connection options and
>> save you from inventing syntax which doesn't expose all options.
>>
>> In the meantime it would be nice if the syntax exposed all options.
>
> So without the capability to pass custom options to block drivers, am I forced
> to keep extending the file= with more and more options ?
>
> file=gluster:transport:server:port:volname:image ?
>
> Looks ugly and not easy to make any particular option optional. If needed I 
> can
> support this from GlusterFS backend.

Kevin, Markus: Any thoughts on passing options to block drivers?
Encoding GlusterFS options into a "filename" string is pretty
cumbersome.