Exchange 12 to axe Active/Active Clustering?

by Bharat Suneja

Oliver Rist’s Enterprise Windows column in InfoWorld talks about many facts/announcements related to the Exchange Server product roadmap – most of it discussed/announced at TechEd in Orlando and at other venues.

He also talks about Active/Active clustering being history with Exchange 12. I’m a little surprised – I thought Microsoft would perhaps work towards making Active/Active Clustering a more elegant High Availability solution – for those who do want to go that route despite all its pitfalls.

Read the complete column on

Replicate the Store: One of the most exciting things for Exchange admins would perhaps be log shipping or synchronous replication of the Exchange store. That’s the biggest single point of failure in clustered Exchange environments. Some NAS/SAN vendors have Exchange solutions in place that do replicate or clone the store using different methods, but it’d be nice to have Exchange (and Microsoft) support it natively without any third-party tools.

{ 2 comments… read them below or add one }

lourh April 25, 2007 at 6:51 am

thanks for this publication!

i have a question, how many nodes can be supported by exchange 12, can we have a A/A/P/P configuration?




Bharat Suneja April 25, 2007 at 2:48 pm

Exchange Server 2007 (RTM) supports “Single Copy Cluster” (SCC) – which is similar to the clustering model we’ve seen in Exchange Server 2003/2000. You have a single copy of Exchange Stores that resides on shared storage. The support is unchanged from Exchange Server 2003 – up to 8 nodes, Active/Active is no longer supported (at least one node needs to be passive). So, yes – A/A/P/P configuration will work.

In addition to the above, do consider the new clustering model – “Cluster Continuous Replication” (CCR). This is supported in 2-node configurations, doesn’t require shared storage, and in fact eliminates the shared storage as a single point of failure. Databases are replicated to the passive node using log shipping.

Also note, clustered mailbox servers (whether CCR or SCC) can only have the Mailbox Server role.


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