Short post!
What is important when planning your SCCM deployment ? Plan for High Availability! (among other things)
SCCM can span from a simple to a very complex solution And it can also be in a complex hierarchy as well. So it is important to know “where do I need to deploy multiple servers in order to have HA” in SCCM?
* ConfigMgr clients can use any of the available servers. If you have multiple Management Points the clients will try to contact one of them, if the one they try to contact is offline they will try the other one. If both servers are offline, the client will cache the data until a MP server is back up. Same goes for distribution points (If the content the client is looking for is located on that DP.
If a client fails to submit data, the site can generate an alert in the console.
* ConfigMgr Database use an SQL cluster for the primary site or at the CAS (IF you have one) Secondary sites does not support SQL clusters, to recover that you would need to reinstall the secondary site. You also do need to remember that you can setup a maintance task to take a backup of the ConfigMgr Site.
* ConfigMgr Sites you can use CAS(Central Administration site) with Primary child sites (This can provide you with fault tolerance if you have an deployment that requires a CAS) But DO not deploy a CAS server if you aren’t sure that you need it.
* ConfMgr Roles you can install multiple instances of roles such as (management points and distribution points) to provide redundancy for the clients. Remember that if you deploy multiple distribution points that if you want a client to failover to the other distribution points that the are within the boundary group.
* Active Directory if you are using AD publishing(and most are), remember that the client will query AD to find its MP and site, so remember that you will need multiple domain controllers (not only to load balance the queries but to provide HA) This goes for DNS as well, unless you are running another DNS server like bind.
* PKI ConfigMgr is very much reliant on certificates for securing traffic, remember that you should have 2 subordinate CA’s that can issue certificates.
Just some last notes, if you are using ConfigMgr you should have OpsMgr as well, use it to monitor your ConfigMgr, AD and ADCS solution!
There is a management pack available to monitor ConfigMgr within OpsMgr you can find it here –>
http://systemcenter.pinpoint.microsoft.com/en-US/applications/monitoring-pack-for-system-center-2012-configuration-manager-12884938509
NOTE: There are some roles that aren’t meant for HA, this includes:
Endpoint Protection Point
Site Server
Asset Intelligence synchronization point
Enrollment point & Enrollment point proxy
Fallback status point
Out of band service point