[ovirt-users] Local Storage

[Andrea Ghelardi]

Hi Scott,
Thank you for your reply. I indeed scratched my face on the wall due to
this approach.
However, we are taking care not to mix iscsi shared and local shared LUNs
on the same datastore.
I understand this is unsupported and discouraged as well but not so
tragic?

Cheers
AG

-----Original Message-----
From: users-bounces at ovirt.org [mailto:users-bounces at ovirt.org] On Behalf
Of Scott Worthington
Sent: Thursday, May 07, 2015 8:20 PM
To: users at ovirt.org
Subject: Re: [ovirt-users] Local Storage

On 5/7/2015 12:11 PM, Andrea Ghelardi wrote:
> It is true that you cannot mix local and shared storage types.
>
> However, it is actually possible tricking local storage to be
> presented as a shared iscsi volume and then passed to ovirt
>
> There are drawbacks but we are actively using this solution.
>
> Cheers
>
> AG

Hello,

The major point that needs to be stressed again and again on this mailing
list is:

At this time, it is best practice to _NEVER_ combine the shared storage
onto the cluster hosts.

There are MANY many MANY posts from people with down oVirt environments
because they combined their shared storage on their hosted cluster
(especially gluster storage).

They do not fully understand the horrible consequences that will happen
when 1) a host cluster node gets fenced, 2) their gluster cluster becomes
split-brained because they failed to understand gluster and quorums, or 3)
a network connectivity issue of some sort breaks the storage cluster on
one (or many) node(s) and then the issue cascades to the other systems
bringing the entire shared storage + clustered hosts to a grinding halt.

As a consequence, this mailing list gets flooded with pleas for help from
a crashed oVirt setup that did not follow best practices.

In my opinion, those who combine shared-storage onto the host-nodes need
to pull the plug on one of their hosts, and then work through the numerous
issues that will result in their hyper-converged configuration.

If the SysAdmin does not have that experience of working through all of
the problems that result from hyper-converging shared storage on the host
nodes, then they certainly need to avoid combing shared storage on the
host nodes.

Good Luck!
--ScottW

_______________________________________________
Users mailing list
Users at ovirt.org
http://lists.ovirt.org/mailman/listinfo/users