[Lustre-discuss] Fwd: Lustre Thumper Fault Tolerance

[Brian J. Murrell]

On Thu, 2008-03-06 at 08:30 -0600, nathan at robotics.net wrote:
> 
> Is there any way to get redundancy from lustre when disk is local to each 
> node and not shared between nodes?

Achieving that is the entire subject of this thread.  Go back to my
first response.  DRBD.

I mistakenly said that DRBD requires more than a 2x total investment
prior.  That of course is wrong.  For HA one is going to have the second
node hardware anyway, whether it's shared disk or otherwise.  The extra
cost of hardware to DRBD is 2x the disk plus the cost of the
interconnect (for DRBD) between the nodes.  This could effect a net
savings depending on the cost of shared disk that you would use
otherwise.

> So far the only way I can see to get a 
> redundant system is to use shared storage and HA.

DRBD is kinda like poor-man's shared storage.  It's not really, but it
achieves fairly close to the same goal.

b.