OpenPages support for admin server failover

We're working on configuring OpenPages 7 WebSphere with multiple
servers. Investigation by our on-site IBM consultant has
discovered that OpenPages segments servers as either an admin server
or managed servers, which isn't called out in Chapter 14 with respect
to Windows Server.

There also appears to be limitations surrounding the "admin server",
specifically that you cannot build a redundant DR node.

Separate to this, there's also a WebSphere component called the
Deployment Manager which is also only installed on the admin server,
again not called out in Chapter 14. This also appears to suffer from
the limitation of not being able to build the Deployment Manager
capability into a second node for DR purposes.

I note there's an IBM article which talks about Deployment Manager HA
(https://www-01.ibm.com/support/knowledgecenter/SSEQTP_8.5.5/com.ibm.websphere.nd.multiplatform.doc/ae/twve_xdsoconfig.html),
but our advice from engineering is that we cannot have a secondary Deployment Manager node.

What we understand so far:
a) The admin server controls synchronisation between itself and managed servers. Precisely what isn't clear.
b) The admin server cannot be installed onto another server, to provide DR services.
c) The admin server, should it require a rebuild, requires a rebuild of all managed servers (in our case up to three).
d) The newly built managed servers cannot be attached to an existing admin server.
e) There are HA options for the Deployment Manager, but we understand this isn't an option for the OpenPages implementation of WebSphere.

This enhancement is to:
1) Update the product offering (and documentation) to provide DR
options for the "admin server". Backups alone aren't the answer.

2) Update the product offering (and documentation) to provide DR
options for the Deployment Manager. Backups alone aren't the answer.

3) Update the product offering so that a rebuild of the "admin server"
doesn't require a rebuild of every "managed server".