Hi, I've just taken over support of an SME with approx 180 staff. There are two sites: Site A = Data Centre with all production servers Site B = Customer office with all staff and a few servers for DR use. 100MB VLAN between sites. We currently have a 2 node Exchange 2003 Active / Passive cluster. Both Nodes are in the same rack in the Data Centre (Site A) which is far from ideal! We have a 3rd Exchange server sitting as hot standby in Site B. The current DR procedure is to restore mailstores from tape to this DR server - this, again,is far from ideal! It has been suggested that this DR server, in Site B,is added as a third node to the cluster. (Uninstall Exchange, install cluster services, re-install Exchange as cluster aware, add node to the cluster.) We know if we lose Site A or the comms to Site A we will lose all external mail as all external access goes through Site A, however internal mail should still be available with Exchange running on Node 3 at Site B. Question - If we then have a 3 node A/P/P cluster and lose comms between the two sites will Exchange automatically fail over to Node 3 within Site B to provide continuity of internal email. Also is there any benefit in keeping the passive Node 2 within Site A or would we be better redeploying this and reverting the cluster to a two node A/P cluster stretched over the two sites. Many Thanks, Anthony.

Just had another thought.... Rather than add the DR server as a third node would it be better to just MOVE the current passive Node 2 from Site A to Site B and continue with a 2 Node A/P cluster. The DR server can then be redeployed for other tasks. If we have a 2 Node cluster stretched across the 2 sites what would happen if we lost the link between both sites? Site A------------------------------------------ Site B Active Node (1) Passive Node (2) + All Users As far as the Active Node (1) is concerned it is still up but has lost site of Node 2. As far as Passive Node (2) is concerned it is still up but has lost site of Node 1. Will Node 2 become the active node? Will Node 1 still be active as far as it is concerned (but not servicing any users)? What will happen when the link is re-established? Any thoughts? Thanks. A.