hello.
I am using glusterfs 3.0.3. and I think it is a realy cool project.
thanks a lot to all developers.
my idea was to use glusterfs for a centralized and highavailability
backend-storage for virtual xen-domus. but I had different errors in
my tests. what I have done:
2x server as glusterfs-server - called server[1,2]
1x server as clusterfs-client - called client1
example gluster-config on the servers:
---------------------
volume brick1
type storage/posix
option directory /test
end-volume
# posix locks
volume brick1-locks
type features/posix-locks
subvolumes brick1
end-volume
volume brick2
type protocol/client
option transport-type tcp/client
option remote-host 192.168.11.214 # IP address of server2
option remote-subvolume brick1-locks # use brick1 on server2
end-volume
volume replicate
type cluster/replicate
subvolumes brick2 brick1-locks
end-volume
volume server
type protocol/server
option transport-type tcp/server
subvolumes brick1-locks replicate
option auth.ip.brick1-locks.allow 192.168.11*,127.0.0.1
option auth.ip.replicate.allow 192.168.11*,127.0.0.1
end-volume
---------------------
on client1
* I run xen 3.4.1
* I have "mounted" glusterfs from server[1,2] -> in this mount-point
there is my xen-image
so my idea is following:
if server1 has a problem or has to be shutdown -> then the xen-image
has to run on server2 without interruption and errors
if server2 has a problem or has to be shutdown -> then the xen-image
has to run on server1 without interruption and errors
so I tried both - server-side-replication and client-side-replication.
here are my test-results:
client-side-replication
---------------------
* I shut down (killed) server1 -> the xen-domu runs further on server2
without any interruption
* after server1 comes up again -> self-healing takes places -> the
virtual xen-domu is not reachable until self-healing ends
server-side-replication
---------------------
with server-side-replication I tried 2 different configuration. one
with HA and one with round robin dns -> both have the same result.
-> HA: the client has not mounted the glusterfs-mount via the real
address of server1 or server2 -> but it has mounted it via a
HA-IP-adress between server1 and server2 -> so if one of the servers
has a problem, the HA-IP will be switched
-> rrdns: like explained here:
http://gluster.com/community/documentation/index.php/High-availability_storage_using_server-side_AFR
the result of both possibilitys:
* I shut down (killed) server1 -> the xen-domu runs further on server2
but there are many errors -> I have to stop the xen-domu and start it
again -> then everything seems to be fine
* after server1 comes up again -> self-healing takes places -> the
virtual xen-domu is not reachable until self-healing ends (same
problem as with the client-side-replication)
so my question is:
is it possible to have a centralized, high availablity glusterfs
storage for virtual images?
if so, what am I doing wrong?
if not so, why?
if I forgot something to mention or you need another config-file,
please be so kind and tell me. I will give it to you.
thank you very very much!!
arian
