[Gluster-users] Need help for production setup

[Vijay Bellur]

On 08/18/2014 11:51 AM, Punit Dambiwal wrote:
> Hi Vijay,
>
> Thanks for the updates..that means if we use replica=3...then there is
> no need to user HW raid ??
>

Yes, HW raid with replica 3 is not essential.

> As i want to use it with Ovirt with HA....would you mind to let me know
> how i can achieve this ??
>
> 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...

How do you plan to have replica 3 with 8 bricks?

> 2. Now attached this gluster storge to ovrit-engine with the following
> mount point 10.10.10.2/vol1 <http://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 ??

If mount has already happened, hypervisor hosts can still access 
storage. To provide HA for mount operation, you can use 
backup-volfile-server option as described in man for mount.glusterfs [1].

> 5. What happen if SPM goes down ???
>

I am not too familiar about the implications of SPM going down. Seems 
like this question is more appropriate for ovirt mailing lists.

> Note :- What happen for point 4 &5 ,If storage and Compute both working
> on the same server.

If storage & compute are on the same server, VM migration before a 
server goes offline would be necessary. A VM can continue to operate as 
long as the mount point on the compute node can reach other bricks that 
are online in a gluster volume. I would also recommend to test the 
implications of self-healing in your test setup after a failed node 
comes back online as the self-healing process can compete for compute 
cycles.

-Vijay


[1] https://github.com/gluster/glusterfs/blob/master/doc/mount.glusterfs.8


>
> Thanks,
> Punit
>
>
> On Mon, Aug 18, 2014 at 1:44 PM, Vijay Bellur <vbellur at redhat.com
> <mailto:vbellur at redhat.com>> wrote:
>
>     On 08/18/2014 09:11 AM, Punit Dambiwal wrote:
>
>         Hi Juan,
>
>         Understand...but if i am using replica=3 then ?? As using the HW
>         raid
>         with commodity HDD will be not good choice...and if i choose HW raid
>         with enterprise grade HDD then cost will be higher and then
>         there will
>         be no use to choose glusterfs for storage...
>
>
>     For replica 3, I don't think hardware RAID would be beneficial. HW
>     raid is recommended for replica 2 scenarios with gluster to provide
>     an additional degree of redundancy.
>
>     -Vijay
>
>
>
>
>
>