qemu/qapi
Prasanna Kumar Kalever 6c7189bb29 block/gluster: add support for multiple gluster servers
This patch adds a way to specify multiple volfile servers to the gluster
block backend of QEMU with tcp|rdma transport types and their port numbers.

Problem:

Currently VM Image on gluster volume is specified like this:

file=gluster[+tcp]://host[:port]/testvol/a.img

Say we have three hosts in a trusted pool with replica 3 volume in action.
When the host mentioned in the command above goes down for some reason,
the other two hosts are still available. But there's currently no way
to tell QEMU about them.

Solution:

New way of specifying VM Image on gluster volume with volfile servers:
(We still support old syntax to maintain backward compatibility)

Basic command line syntax looks like:

Pattern I:
 -drive driver=gluster,
        volume=testvol,path=/path/a.raw,[debug=N,]
        server.0.type=tcp,
        server.0.host=1.2.3.4,
        server.0.port=24007,
        server.1.type=unix,
        server.1.socket=/path/socketfile

Pattern II:
 'json:{"driver":"qcow2","file":{"driver":"gluster",
       "volume":"testvol","path":"/path/a.qcow2",["debug":N,]
       "server":[{hostinfo_1}, ...{hostinfo_N}]}}'

   driver      => 'gluster' (protocol name)
   volume      => name of gluster volume where our VM image resides
   path        => absolute path of image in gluster volume
  [debug]      => libgfapi loglevel [(0 - 9) default 4 -> Error]

  {hostinfo}   => {{type:"tcp",host:"1.2.3.4"[,port=24007]},
                   {type:"unix",socket:"/path/sockfile"}}

   type        => transport type used to connect to gluster management daemon,
                  it can be tcp|unix
   host        => host address (hostname/ipv4/ipv6 addresses/socket path)
   port        => port number on which glusterd is listening.
   socket      => path to socket file

Examples:
1.
 -drive driver=qcow2,file.driver=gluster,
        file.volume=testvol,file.path=/path/a.qcow2,file.debug=9,
        file.server.0.type=tcp,
        file.server.0.host=1.2.3.4,
        file.server.0.port=24007,
        file.server.1.type=unix,
        file.server.1.socket=/var/run/glusterd.socket
2.
  'json:{"driver":"qcow2","file":{"driver":"gluster","volume":"testvol",
         "path":"/path/a.qcow2","debug":9,"server":
         [{"type":"tcp","host":"1.2.3.4","port":"24007"},
          {"type":"unix","socket":"/var/run/glusterd.socket"}
         ]}}'

This patch gives a mechanism to provide all the server addresses, which are in
replica set, so in case host1 is down VM can still boot from any of the
active hosts.

This is equivalent to the backup-volfile-servers option supported by
mount.glusterfs (FUSE way of mounting gluster volume)

credits: sincere thanks to all the supporters

Signed-off-by: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1468947453-5433-6-git-send-email-prasanna.kalever@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-07-19 17:38:50 -04:00
..
block-core.json block/gluster: add support for multiple gluster servers 2016-07-19 17:38:50 -04:00
block.json qmp event: Refactor QUORUM_REPORT_BAD 2016-03-14 16:46:43 +01:00
common.json kvm: add support for -machine kernel_irqchip=split 2015-12-17 17:15:40 +01:00
crypto.json crypto: implement sha224, sha384, sha512 and ripemd160 hashes 2016-07-04 15:52:36 +01:00
event.json qmp event: Refactor QUORUM_REPORT_BAD 2016-03-14 16:46:43 +01:00
introspect.json qapi: Use anonymous bases in QMP flat unions 2016-03-18 10:29:26 +01:00
Makefile.objs qapi: Add new clone visitor 2016-07-06 10:52:04 +02:00
opts-visitor.c opts-visitor: Favor new visit_free() function 2016-07-06 10:52:04 +02:00
qapi-clone-visitor.c qapi: Add new clone visitor 2016-07-06 10:52:04 +02:00
qapi-dealloc-visitor.c qapi: Add new visit_free() function 2016-07-06 10:52:04 +02:00
qapi-util.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
qapi-visit-core.c qapi: Add new clone visitor 2016-07-06 10:52:04 +02:00
qmp-dispatch.c qapi: Improve use of qmp/types.h 2016-07-06 10:52:03 +02:00
qmp-event.c qapi: Clean up includes 2016-02-04 17:41:30 +00:00
qmp-input-visitor.c qmp-input-visitor: Favor new visit_free() function 2016-07-06 10:52:04 +02:00
qmp-output-visitor.c qapi: Add new visit_complete() function 2016-07-06 10:52:04 +02:00
qmp-registry.c all: Remove unnecessary glib.h includes 2016-06-07 18:19:24 +03:00
rocker.json qmp/hmp: add rocker device support 2015-06-12 13:42:17 +01:00
string-input-visitor.c string-input-visitor: Favor new visit_free() function 2016-07-06 10:52:04 +02:00
string-output-visitor.c qapi: Add new visit_complete() function 2016-07-06 10:52:04 +02:00
trace.json trace: Add QAPI/QMP interfaces to query and control per-vCPU tracing state 2016-07-18 18:23:12 +01:00