In the Remote Ops Mgr deployment guide, you'll notice we've given guidance to help you plan your Remote Operations Manager deployment. A standard Remote Ops Mgr deployment is very similar to a multiple server, single management group Ops Mgr deployment, but there are a few differences I want to point out.
First, you'll need a least a Root Management Server to create the management group. For fault-tolerance you can cluster the Root Management Server. You'll also need a database server which also can be hosted on a SQL 2005 cluster for fault-tolerance. Next, you'll need to use an internet-facing gateway management servers for communication between the root management server and each Essentials server at your customer sites. Again, to provide fault tolerance you can use multiple internet-facing gateway management servers, configuring the Essentials server to failover from a primary gateway to a backup in case of failure.
Optionally, you can install a web console server to provide live monitoring views for your customers if they desire this capability.
To scale your Remote Ops Mgr deployment, you'll need to add additional management servers and internet-facing gateways. A management server can monitor a maximum of 2000 agents; once your Remote Ops Mgr management group reaches this threshold, you'll need to add additional management servers. An internet-facing gateway can monitor a maximum of 530 agents (which is also the maximum number of computers that can be managed by one Essentials server.
Take the example that you are managing 20 customers who each have 200 computers. To support this Remote Ops Mgr deployment, you'd need at least two management servers and eight internet-facing gateway servers, but for fault-tolerance you should consider having additional management servers and gateways available as failover servers in case of an outage.
To reduce the amount of hardware needed to support the required gateway, you could run the gateway management servers in a virtual server. Since Remote Ops Mgr is licenses through the Service Provider Licensing Agreement, adding additional management servers does not increase the incur additional licensing costs.
Maximum number of agents that can be monitored through one management server: 2000
Maximum number of agents that can be monitored through one gateway management server: 530
Maximum number of agents managed by an Essentials server in service provider mode: 530 (30 Windows Servers and 500 Windows clients)
To assist with modeling the required infrastructure for a Remote Ops Mgr deployment, you'll also be able to use the soon-to-be-released System Center Capacity Planner to plan for your Remote Operations Manager deployment.