6c7189bb29
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>
QEMU
QEMU is a generic and open source machine & userspace emulator and virtualizer.
QEMU is capable of emulating a complete machine in software without any need for hardware virtualization support. By using dynamic translation, it achieves very good performance. QEMU can also integrate with the Xen and KVM hypervisors to provide emulated hardware while allowing the hypervisor to manage the CPU. With hypervisor support, QEMU can achieve near native performance for CPUs. When QEMU emulates CPUs directly it is capable of running operating systems made for one machine (e.g. an ARMv7 board) on a different machine (e.g. an x86_64 PC board).
QEMU is also capable of providing userspace API virtualization for Linux and BSD kernel interfaces. This allows binaries compiled against one architecture ABI (e.g. the Linux PPC64 ABI) to be run on a host using a different architecture ABI (e.g. the Linux x86_64 ABI). This does not involve any hardware emulation, simply CPU and syscall emulation.
QEMU aims to fit into a variety of use cases. It can be invoked directly by users wishing to have full control over its behaviour and settings. It also aims to facilitate integration into higher level management layers, by providing a stable command line interface and monitor API. It is commonly invoked indirectly via the libvirt library when using open source applications such as oVirt, OpenStack and virt-manager.
QEMU as a whole is released under the GNU General Public License, version 2. For full licensing details, consult the LICENSE file.
Building
QEMU is multi-platform software intended to be buildable on all modern Linux platforms, OS-X, Win32 (via the Mingw64 toolchain) and a variety of other UNIX targets. The simple steps to build QEMU are:
mkdir build
cd build
../configure
make
Complete details of the process for building and configuring QEMU for all supported host platforms can be found in the qemu-tech.html file. Additional information can also be found online via the QEMU website:
http://qemu-project.org/Hosts/Linux
http://qemu-project.org/Hosts/W32
Submitting patches
The QEMU source code is maintained under the GIT version control system.
git clone git://git.qemu-project.org/qemu.git
When submitting patches, the preferred approach is to use 'git format-patch' and/or 'git send-email' to format & send the mail to the qemu-devel@nongnu.org mailing list. All patches submitted must contain a 'Signed-off-by' line from the author. Patches should follow the guidelines set out in the HACKING and CODING_STYLE files.
Additional information on submitting patches can be found online via the QEMU website
http://qemu-project.org/Contribute/SubmitAPatch
http://qemu-project.org/Contribute/TrivialPatches
Bug reporting
The QEMU project uses Launchpad as its primary upstream bug tracker. Bugs found when running code built from QEMU git or upstream released sources should be reported via:
https://bugs.launchpad.net/qemu/
If using QEMU via an operating system vendor pre-built binary package, it is preferable to report bugs to the vendor's own bug tracker first. If the bug is also known to affect latest upstream code, it can also be reported via launchpad.
For additional information on bug reporting consult:
http://qemu-project.org/Contribute/ReportABug
Contact
The QEMU community can be contacted in a number of ways, with the two main methods being email and IRC
- Mailing List: qemu-devel@nongnu.org
- Archives: http://lists.nongnu.org/mailman/listinfo/qemu-devel
- IRC: #qemu on irc.oftc.net
Information on additional methods of contacting the community can be found online via the QEMU website: