On Thu, Dec 31, 2015 at 3:44 AM, Donny Davis <donny@cloudspin.me> wrote:
I would say you would be much better off picking two hosts to do your HE on and setting up drdb for the HE storage. You will have fewer problems with your HE.
Is drdb an oVirt thing? Or are you suggesting a db backup or replicated sql db solution that I would cut over to manually.
On Thu, Dec 31, 2015 at 1:41 AM, Sahina Bose <sabose@redhat.com> wrote:
If you mean, creating new gluster volumes - you need to make sure the gluster service is enabled on the Default cluster. The cluster that HE creates, has only virt service enabled by default. Engine should have been installed in "Both" mode like Roy mentioned.
I went over those settings with limited success. I went through multiple iterations of trying to stand up HE on gluster storage. Then I gave up on that and tried NFS storage. Ultimately it always came down to sanlock errors (both gluster and NFS storage). I tried restarting the sanlock service, which would lead to watchdog rebooting the hosts. When the host came back up it almost seemed like things had started working. I could see begin to see/create gluster volumes (see hosted_storage, or begin to create a data storage domain) But when I would try to activate the hosted_storage domain things would start to fall apart again. sanlock as far as I can tell. I am currently running the engine on a physical system and things are working fine. I am considering taking a backup and attempting to use the HE physical to VM migration method, time permitting.
On 12/28/2015 12:43 AM, Roy Golan wrote:
3 way replica is the officially supported replica count for VM store use case. If you wish to work with replica 4, you can update the supported_replica_count in vdsm.conf
Thanks for that insight. I think I just experienced the bad aspects of both quorum=auto and quorum=none. I don't like replica 3, because you can only have one brick offline at a time. I think N+2 should be the target for a production environment. (so you have the capacity for a failure while doing maintenance). Would adding an arbiter effect the quorum status? Is 3x replica and 1x arbiter considered a replica 3 or 4?
No chicken and egg here I think. You want a volume to be used as your master data domain and creating a new volume in a new gluster-cluster is independent of your datacenter status.
You mentioned your hosts are on default cluster - so make sure your cluster support gluster service (you should have picked gluster as a service during engine install)
I chose "both" during engine-setup, although I didn't have "gluster service" enable on the default cluster at first. Also vdsm-gluster rpm was not installed (I sort of feel like 'hosted-engine --deploy' should take care of that. Adding a host from my current physical engine using the "add host" gui didn't bring it in either. Thanks for the input!