[ovirt-users] Local Storage

[Scott Worthington]

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