On Sat, Dec 21, 2013 at 4:43 AM, <gregoire.leroy@retenodus.net> wrote:

Hi,

keepalived is only for grabbing the gluster volume info (eg. the servers which host the bricks) > in which from what I've noticed your clients will then connect to the gluster servers directly
(not using keepalived anymore).

Can't keepalived be replace by naming the hostname by localhost, as what Alex says ?

Yes it could sorry I forgot about that method, I used to do it that way but we had plans on possibly implementing nodes without glusterfs bricks possibly in the future so we moved to keepalived.

If you disable quorum then you won't have the issue of "read only" when you lose a host, but you > won't have protection from split brain (if your two hosts lose network connectivity). VMs will
keep writing to the hosts, as you have the gluster server and client on the same host this is
inevitable.

Ok, I get the problem caused by disabling the quorum. So, what if while I've two hosts the lack of HA is not so dramatic but will be necessary when I'll have more hosts ? (3 or 4). Here is the scenario I would like to have :

Quorum generally requires 3 hosts, I believe the default configuration when you press "Optimize for virt store" will require a minimum of 2 bricks connected before writing is allowed.

1) I have two hosts : HOSTA and HOSTB. They have glusterfs bricks configured as Distribute Replicated and data is replicated.
=> For now, I'm totally ok with the fact that if a node fails, then VM on this hosts are stopped and unreachable. However, I would like that if a node fails, the DC keeps running so that VM on the other hosts are not stopped and a human intervention make possible to start the VM on the other host. Would it be possible without disabling the quorum ?

For the 2 host scenario, disable quorum will allow you to do this.

2) In few months, I'll add two other hosts to the glusterfs volum. Their bricks will be replicated.
=> At that time, I would like to be able to make evolve my architecture (without shut my VM and export/import them on a new cluster) so that if a node fails, VM on this host start to run on the other host of the same brick (without manual intervention).

Later on you just enable quorum, it's only a setting in the gluster volume.

gluster volume set DATA cluster.quorum-type auto

Is it possible ?

Le 2013-12-20 16:22, a.ludas@gmail.com a écrit :

Hi,

in a 2 node cluster you can set the path to localhost:volume. If one
host goes down and SPM role switches to the remaining running host,
your master domain is still accessible and so your VMs stay up and
running.

Regards,
Alex

I tried it but still, the storage/cluster were shutdown, probably because of the quorum.

Thank you very much,
Regards,
Grégoire Leroy