[Info-vax] Looking to remote cluster my two OVMS machines. Questions. Need help!!!

[Stephen Hoffman]

On 2012-10-12 09:09:02 +0000, Hans Vlems said:

> A solution that works fine for me is to give each node in a two node
> NI cluster its own quorum disk.
> The quorum disk is local to that node. Each disk and each host have
> one vote. If both nodes are running
> then the quorumdisks do not participate in the voting process. As soon
> as one node leaves the luster the
> remaining node discovers its quorum disk, adds one vote and keeps on
> running.
> This is not a supported configuration though. An NI might loose its
> network connection, especially on large LANs.
> If that happens then both nodes will decide that the other one crashed
> and recover as described.
> Unfortunately when the LAN comes on-line then the hosts will, or may
> not, recognize each other. At this "rediscovery"stage
> the cluster status is undefined and all kinds of things (especially
> datastructures) may fail.
> For simple applications that just share files this set up works fine.
> Hans

That seems to be a dependency on a bug and not a bug that I'd 
particularly want to rely on, either; that the quorum disk is being 
"discovered".

That could lead to partitioning on link failure (as alluded) and the 
OP-requested configuration is centrally built on a ~15 Mb LAN link.

Though with little data, the worst that can probably happen are both 
lobes operating and entirely uncoordinated.  (Which could play havoc 
with DNS connections into the configurations, for that matter.  They'll 
work, and now you have two "live" systems accruing changes.)

With a local configuration of Alpha PCI boxes, get two TCQ SCSI 
controllers and go shared-SCSI.

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