[ovirt-users] Glusterfs HA with Ovirt

[Andrew Lau]

Don't forget to take into consideration quroum, that's something
people often forget

The reason you're having the current happen, is gluster only uses the
initial IP address to get the volume details. After that it'll connect
directly to ONE of the servers, so with your 2 storage server case,
50% chance it won't go to paused state.

For the VIP, you could consider CTDB or keepelived, or even just using
localhost (as your storage and compute are all on the same machine).
For CTDB, checkout
http://community.redhat.com/blog/2014/05/ovirt-3-4-glusterized/

I have a BZ open regarding gluster VMs going into paused state and not
being resumable, so it's something you should also consider. My case,
switch dies, gluster volume goes away, VMs go into paused state but
can't be resumed. If you lose one server out of a cluster is a
different story though.
https://bugzilla.redhat.com/show_bug.cgi?id=1058300

HTH

On Fri, Jul 4, 2014 at 11:48 AM, Punit Dambiwal <hypunit at gmail.com> wrote:
> Hi,
>
> Thanks...can you suggest me any good how to/article for the glusterfs with
> ovirt...
>
> One strange thing is if i will try both (compute & storage) on the same
> node...the below quote not happen....
>
> ---------------------
>
> Right now, if 10.10.10.2 goes away, all your gluster mounts go away and your
> VMs get paused because the hypervisors can’t access the storage. Your
> gluster storage is still fine, but ovirt can’t talk to it because 10.10.10.2
> isn’t there.
> ---------------------
>
> Even the 10.10.10.2 goes down...i can still access the gluster mounts and no
> VM pause....i can access the VM via ssh...no connection failure.....the
> connection drop only in case of SPM goes down and the another node will
> elect as SPM(All the running VM's pause in this condition).
>
>
>
> On Fri, Jul 4, 2014 at 4:12 AM, Darrell Budic <darrell.budic at zenfire.com>
> wrote:
>>
>> You need to setup a virtual IP to use as the mount point, most people use
>> keepalived to provide a virtual ip via vrrp for this. Setup something like
>> 10.10.10.10 and use that for your mounts.
>>
>> Right now, if 10.10.10.2 goes away, all your gluster mounts go away and
>> your VMs get paused because the hypervisors can’t access the storage. Your
>> gluster storage is still fine, but ovirt can’t talk to it because 10.10.10.2
>> isn’t there.
>>
>> If the SPM goes down, it the other hypervisor hosts will elect a new one
>> (under control of the ovirt engine).
>>
>> Same scenarios if storage & compute are on the same server, you still need
>> a vip address for the storage portion to serve as the mount point so it’s
>> not dependent on any one server.
>>
>> -Darrell
>>
>> On Jul 3, 2014, at 1:14 AM, Punit Dambiwal <hypunit at gmail.com> wrote:
>>
>> Hi,
>>
>> I have some HA related concern about glusterfs with Ovirt...let say i have
>> 4 storage node with gluster bricks as below :-
>>
>> 1. 10.10.10.1 to 10.10.10.4 with 2 bricks each and i have distributed
>> replicated architecture...
>> 2. Now attached this gluster storge to ovrit-engine with the following
>> mount point 10.10.10.2/vol1
>> 3. In my cluster i have 3 hypervisior hosts (10.10.10.5 to 10.10.10.7) SPM
>> is on 10.10.10.5...
>> 4. What happen if 10.10.10.2 will goes down.....can hypervisior host can
>> still access the storage ??
>> 5. What happen if SPM goes down ???
>>
>> Note :- What happen for point 4 &5 ,If storage and Compute both working on
>> the same server.
>>
>> Thanks,
>> Punit
>> _______________________________________________
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>> Users at ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/users
>>
>>
>
>
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