So I've tested this today and I failed a node. Specifically, I setup a glusterfs domain and selected "host to use: node1". Set it up and then failed that VM

However, this did not work and the datacenter went down. My engine stayed up, however, it seems configuring a domain to pin to a host to use will obviously cause it to fail

This seems counter-intuitive to the point of glusterfs or any redundant storage. If a single host has to be tied to its function, this introduces a single point of failure

Am I missing something obvious?

On Thu, Aug 31, 2017 at 9:43 AM, Kasturi Narra <knarra@redhat.com> wrote:
yes, right.  What you can do is edit the hosted-engine.conf file and there is a parameter as shown below [1] and replace h2 and h3 with your second and third storage servers. Then you will need to restart ovirt-ha-agent and ovirt-ha-broker services in all the nodes .

[1] 'mnt_options=backup-volfile-servers=<h2>:<h3>' 

On Thu, Aug 31, 2017 at 5:54 PM, Charles Kozler <ckozleriii@gmail.com> wrote:
Hi Kasturi -

Thanks for feedback

> If cockpit+gdeploy plugin would be have been used then that would have automatically detected glusterfs replica 3 volume created during Hosted Engine deployment and this question would not have been asked
  
Actually, doing hosted-engine --deploy it too also auto detects glusterfs.  I know glusterfs fuse client has the ability to failover between all nodes in cluster, but I am still curious given the fact that I see in ovirt config node1:/engine (being node1 I set it to in hosted-engine --deploy). So my concern was to ensure and find out exactly how engine works when one node goes away and the fuse client moves over to the other node in the gluster cluster

But you did somewhat answer my question, the answer seems to be no (as default) and I will have to use hosted-engine.conf and change the parameter as you list

So I need to do something manual to create HA for engine on gluster? Yes?

Thanks so much!

On Thu, Aug 31, 2017 at 3:03 AM, Kasturi Narra <knarra@redhat.com> wrote:
Hi,

   During Hosted Engine setup question about glusterfs volume is being asked because you have setup the volumes yourself. If cockpit+gdeploy plugin would be have been used then that would have automatically detected glusterfs replica 3 volume created during Hosted Engine deployment and this question would not have been asked.

   During new storage domain creation when glusterfs is selected there is a feature called 'use managed gluster volumes' and upon checking this all glusterfs volumes managed will be listed and you could choose the volume of your choice from the dropdown list.

    There is a conf file called /etc/hosted-engine/hosted-engine.conf where there is a parameter called backup-volfile-servers="h1:h2" and if one of the gluster node goes down engine uses this parameter to provide ha / failover. 

 Hope this helps !!

Thanks
kasturi



On Wed, Aug 30, 2017 at 8:09 PM, Charles Kozler <ckozleriii@gmail.com> wrote:
Hello -

I have successfully created a hyperconverged hosted engine setup consisting of 3 nodes - 2 for VM's and the third purely for storage. I manually configured it all, did not use ovirt node or anything. Built the gluster volumes myself

However, I noticed that when setting up the hosted engine and even when adding a new storage domain with glusterfs type, it still asks for hostname:/volumename

This leads me to believe that if that one node goes down (ex: node1:/data), then ovirt engine wont be able to communicate with that volume because its trying to reach it on node 1 and thus, go down

I know glusterfs fuse client can connect to all nodes to provide failover/ha but how does the engine handle this?

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