On Tue, Sep 8, 2015 at 8:32 PM, Daniel P. Berrange <[email protected]> wrote:
> On Tue, Sep 08, 2015 at 06:34:09PM +0530, Prasanna Kumar Kalever wrote: > > This patch adds a way to specify multiple backup volfile servers to the > gluster > > block backend of QEMU with both tcp and rdma transport types. > > > > Problem: > > > > Currenly VM Image on gluster volume is specified like this: > > > > file=gluster[+tcp]://server1:24007/testvol/a.img > > > > Assuming we have have three servers in trustred pool with replica 3 > volume > > in action and unfortunately server1 (mentioned in the command above) > went down > > for some reason, since the volume is replica 3 we now have other 2 > servers > > active from which we can boot the VM. > > > > But currently there is no mechanism to pass the other 2 gluster server > > addresses to qemu. > > > > Solution: > > > > New way of specifying VM Image on gluster volume with backup volfile > servers: > > > > file=gluster[+transport-type]://server1:24007/testvol/a.img\ > > ?backup-volfile-servers=server2&backup-volfile-servers=server3 > > Comparison with RBD syntax: > > file=rbd:pool/image:auth_supported=none:\ > mon_host=mon1.example.org\:6321\;mon2.example.org\:6322\;\ > mon3.example.org\:6322,if=virtio,format=raw > > As Peter already mentioned, you're missing port numbers. > > It is slightly unpleasant to have different ways of specifying the first > vs second, third, etc hosts. I wonder if it would be nicer to keep all > the hostnames in the host part of the URI. eg > > > > file=gluster[+transport-type]://server1:24007,server2:3553,server3:2423/testvol/a.img\ > ?backup-volfile-servers=server2&backup-volfile-servers=server3 > > Of course it ceases to be a wellformed URI at that point, so another option > would be to just allow the host part of the URI to be optional, and then > accept mutliple instances ofa 'server' arg, eg > > file=gluster[+transport-type]:///testvol/a.img\ > ?server=server1:2424&server=server2:2423&sever=server3:34222 > > Is it allowed to have this syntax and be a valid URI ? I admit i haven't looked at the URI rfc for a long time now, hence the Q. Also looking at rbd syntax, it looks to follow this model already is it ? Whats the difference between using ':' to separate key=value pairs Vs using '?" query syntax ? Should we look at having a uniform way of specifying URI be it rbd or gluster or sheepdog ... ? If yes what that uniform syntax be using ':" or '?" ? thanx, deepak > I think I prefer this last syntax most. > > > > > This patch gives a mechanism to provide all the server addresses which > are in > > replica set, so in case server1 is down VM can still boot from any of the > > active servers. > > > > This is equivalent to the backup-volfile-servers option supported by > > mount.glusterfs (FUSE way of mounting gluster volume) > > > > Signed-off-by: Prasanna Kumar Kalever <[email protected]> > > --- > > block/gluster.c | 118 > +++++++++++++++++++++++++++++++++++++++----------------- > > 1 file changed, 83 insertions(+), 35 deletions(-) > > > > static int qemu_gluster_parseuri(GlusterConf *gconf, const char > *filename) > > { > > - URI *uri; > > - QueryParams *qp = NULL; > > - bool is_unix = false; > > - int ret = 0; > > + URI *uri = NULL; > > + QueryParams *qp = NULL; > > + bool is_unix = false; > > + bool is_tcp = false; > > + bool is_rdma = false; > > + int i = 0; > > + int ret = 0; > > + int nservers = 0; > > Aligning indentation like this is really not desirable, as it results > in huge whitespace diffs for existing code anytime someone adds/removes > a variable which changes the indent depth, so please don't do this. > > Regards, > Daniel > -- > |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ > :| > |: http://libvirt.org -o- http://virt-manager.org > :| > |: http://autobuild.org -o- http://search.cpan.org/~danberr/ > :| > |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc > :| > >
