Re: [libvirt] [RFC PATCH v1 1/2] Qemu/Gluster: Add Gluster protocol as supported network disk formats.
On Wed, Sep 5, 2012 at 8:45 PM, Eric Blake <eblake(a)redhat.com> wrote:
On 09/05/2012 09:08 AM, Bharata B Rao wrote:
> On Wed, Sep 5, 2012 at 7:03 PM, Jiri Denemark <jdenemar(a)redhat.com> wrote:
>>> @@ -1042,6 +1043,13 @@
>>> <attribute name="port">
>>> <ref name="unsignedInt"/>
>>> </attribute>
>>> + <attribute name="transport">
>>> + <choice>
>>> + <value>socket</value>
>>> + <value>unix</value>
>>> + <value>rdma</value>
>>
>> This could be a bit confusing as socket is too generic, after all unix is also
>> a socket. Could we change the values "tcp", "unix",
"rdma" or something
>> similar depending on what "socket" was supposed to mean?
>
> That is how gluster calls it and hence I am using the same in QEMU and
> the same is true here too. This is something for gluster developers to
> decide if they want to change socket to something more specific like
> tcp as you suggest.
Just because gluster calls it a confusing name does not mean we have to
repeat the confusion in libvirt - it is feasible to have a mapping where
we name it 'tcp' in the XML but map that to 'socket' in the command line
that eventually reaches gluster. The question then becomes whether
using sensible naming in libvirt, but no longer directly mapped to
underlying gluster naming, will be the cause of its own set of headaches.
Vijay - would really like to have your inputs here...
- While the transport-type for a volume is shown as tcp in "gluster
volume info", libgfapi forces me to use transport=socket to access the
same volume from QEMU. So does "socket" mean "tcp" really ? If so,
should I just switch over to using transport=tcp from QEMU ? If not,
can you explain a bit about the difference b/n socket and tcp
transport types ?
- Also apart from socket (or tcp ?), rdma and unix, are there any
other transport options that QEMU should care about ?
- Are rdma and unix transport types operational at the moment ? If
not, do you see them being used in gluster any time in the future ?
The reason behind asking this is to check if we are spending effort in
defining semantics in QEMU for a transport type that is never going to
be used in gluster. Also I see that "gluster volume create" supports
tcp and rdma but doesn't list unix as an option.
Regards,
Bharata.