[Linux-cluster] Re: Linux-cluster Digest, Preventing LVM from concurrent access

[Edson Marquezani Filho]

On Sun, Aug 23, 2009 at 15:20, David
Hollister<davidhollister at comcast.net> wrote:
> We use HA-LVM in environments where we do not use GFS. It works well in preventing shared storage from being mounted on both nodes simultaneouly. However I am not sure how it would react in a split brain conditon, which appears to be what you are describing. . You should probably consider creating redundancy in your heartbeat via IP Bonding. Basically having two nics on each host bound to one ip.

Indeed, I won't use GFS. Once I don't need any volume to be mounted at
diferent points simultaneously, there is no reason to use it, and I
want to keep my system as simple as possible for my needs.

When you say that HA-LVM prevents shares storage from being mounted on
more than one node, do you mean that I could not do that, even
manually? Or you mean that this won't be done by the cluster
infrastrucuture? AFAIK, when using HA-LVM, the LVM locking keeps
local, right? So, that's the problem to me, because some unware people
could break things.

I have already thought about bonding two interfaces, but the simple
idea of having cables disconnected still sounds very dangerous to me.
Or even if I get master server restarted, when it is back, it would
try to launch virtual machines, but them would be mount on slave. Do
you understand?

I think that's not the correct way for doing what I want, and I'm not
getting how to do this.

How would you do that? (Forget about Heartbeat, it was just the
easiest way I have found for doing this, but what I need is things
working well, it don't matter how. But, I want to keep things not more
complex than necessary.)

Thank you.