In the second half of 2015, Microsoft released a new mail server version under a familiar name – Microsoft Exchange Server 2016. The list of changes proved to be quite short which puzzled the specialists who know the history of the product. If you omit the new year in the product name, it seems that we deal with next Service Pack for Exchange Server 2013. Cloud perspectives of the manufacturer require applying much effort to Office 365, Azure, and On-Premises products are developed as a residual. Despite the changes are not numerous, I’ll try to list the key things that the mail system specialists should know.
- When installing Exchange Server 2016, Mailbox and Edge server roles are available. Speaking another language, the Client Access server role has been removed. In the last four years Microsoft explicitly said that the combination of the Client Access and Mailbox roles was a recommended option. Now, the recommendation has become mandatory; the Client Access role has been absorbed by the Mailbox role, and all proxy services are located in Mailbox.
- The minimum forest functional level Windows Server 2008 required to install Exchange Server. It’s been a long time coming; the life time of Windows Server 2003 officially has run out, so before moving to Exchange Server 2016, we have to get rid of the old version DCs.
- Migration from older versions starting from Exchange Server 2010 is supported. Nothing new is invented here; two previous editions are still supported. But that’s not all, the old systems must be upgraded; Update Rollup 11 has to be installed on Exchange 2010 SP3, and Exchange 2013 should at least have Cumulative Update 10.
- Exchange 2010\2013 and Exchange 2016 can not be in the same DAG, but they may proxy client connections against each other. The namespace can be left the same, and client connections can be balanced to the servers of different versions.
- Either Windows Server 2012 R2 (Standard / Datacenter) or Windows Server 2012 is required as a platform for Exchange Server 2016. It’s still no sense to use Datacenter edition to install Exchange Server 2016.
- The earliest supported version of the mail client is Outlook 2010. All previously released versions have to be removed, and KB2965295 has to be installed to Outlook 2010 itself – it is a mandatory requirement.
- Office Online Server is required to proper work of Exchange Server 2016. When you work with attachments using OWA, while opening the box, documents are converted to be viewed in a browser. Earlier Exchange did this work itself, and since its 2013 version, the option of using Office Web Apps Server 2013 became available. Now, Office Web Apps Server 2013 turned into Office Online Server, and integrated into Exchange, it allows you to edit attachments using OWA. Office Online Server can not be combined with Exchange, and therefore, a separate server or a group of servers are required.
- The migration to Exchange Server 2016 doesn’t require hardware upgrade. System requirements have not changed; the only nuance is associated with an increase of requirements to processor by approximately 25%. So, if your mail system processors worked under maximum load, they won’t feel better after migration.
- DAG is still used for high availability. There are no much changes, but there are some technical nuances. For example, cluster name object is no longer used to create DAG, although the latest versions of Exchange Server 2013 also allowed living without it. Microsoft still recommends using the solutions distributed between data centers, in particular to put two servers in each site, and to place a witness somewhere else, for example, in Azure. In this case, it is possible to use 3 normal copies and one copy of the database with delay in applying changes. All this stuff is recommended to balance by means of DNS and make it hardware, not virtual.
- Exchange Server 2016 supports the ReFS file system for disks with databases. It’s a quite controversial improvement, given that this file system has managed to demonstrate its capriciousness. Enthusiasts had time to test ReFS with the Jetstress utility and compare it with NTFS, and the results of the IOPS measurements in ReFS were by 15% weaker, but the load on the processor when dealing with the database in ReFS was lower.
- MAPI-over-HTTP, which appeared in Exchange Server 2013, is enabled by default now and is the mail for client connection. It was finally decided to get rid of RPC-over-HTTP and all mention of it will be removed from the product in the following version.
- Outlook 2016 is a basic client for Exchange Server 2016. The most interesting is that getting rid of older versions is all around. Outlook 2016 supports only Exchange Server 2010 or higher. The manual configuration of the connection has been removed in it, and only Autodiscover is available now. The ability to add links to files from cloud storages as attachments is one of the tastiest product features.
As a result, it is a logical extension of Exchange Server 2013 with certain qualitative changes. In addition to the announced things, Microsoft has added search in shared folders via using “In-Place eDiscovery and In-Place Hold” feature, and slightly expanded the DLP opportunities. The first year of mass use will demonstrate how qualitative the product has become. However, of course, with such a list of changes, it will be difficult to persuade people to migrate from Exchange Server 2013.