Exchange Server 2016 to Deploy
If
you’re planning aExchange Server 2016 deployment you will need to consider which edition of the
product to deploy on your servers.
For
Exchange Server 2016 there are two editions of the server product itself, and
there is only one difference between them which is the number of mounted
databases per server.
- Exchange Server 2016 Standard Edition – maximum of 5 mounted databases per server
- Exchange Server 2016 Enterprise Edition – maximum of 100 mounted databases per server
Microsoft’s
definition of a “mounted database” is:
A
mounted database can be an active mailbox database that is mounted for use by
clients, or a passive mailbox database that is mounted in recovery for log
replication and replay. While you can create more databases than the limits
described above, you can only mount the maximum number specified above. The
recovery database does not count towards this limit.
Here’s
a few examples. In this example a single Mailbox server running Standard
Edition has 5 mailbox databases. All 5 databases will be able to mount, and an
additional recovery database can also be created and mounted for any data
restoration scenarios.
What
about a database availability group? DAGs can have up to 16 members, and each
member is limited by the edition of Exchange Server 2016 that is installed. So
a Standard Edition DAG member can host up to 5 active or passive
database copies, and an Enterprise Edition DAG member can host up to 100
active or passive database copies. The DAG itself is only limited by the
capabilities of all of its members. A DAG made up of 16 Standard Edition
members, with each database having 4 copies, could therefore host up to 20
databases.
To
be clear, there is no requirement to run Exchange Server 2016 Enterprise
Edition just because you’re deploying a DAG. The choice of server edition is
purely driven by the number of mounted databases each server will be hosting.
For
the Edge Transport role, given it does not host any databases, it makes sense
to use a Standard Edition server license.
When
you purchase your Exchange Server 2016 server licenses you’ll be provided with
a license key that needs to be entered on the server. The license keys determines
which server edition is installed, there is no different in installation media
or installation method for each edition. All servers are first installed as a
Trial Edition, and then you add your license key after installation is
complete. You can upgrade from Trial to Standard, or from Trial to Enterprise.
You can also upgrade from Standard to Enterprise. However, you can’t downgrade
from Enterprise to Standard without completely reinstalling the server. This
means it is feasible to initially license your servers as Standard Edition, and
then later upgrade them to Enterprise Edition if your environment scales up
(e.g. if there is a corporate acquisition or merger).
As
a final note, the information above applies only to the server licenses. The
Client Access Licenses (CALs) are considered separately, and have no impact on
the server license you choose to deploy and vice versa.
Comments