Migrating a small organization from Exchange 2010 to Exchange 2016 (Part 1)

If you would like to read the other parts in this article series please go to:


The latest version of Exchange Server brings the latest cloud-based developments and reliability improvements to on-premises Exchange. In this series we will walk through the steps required to implement Exchange 2016 into your current Exchange 2010 organization and migrate mailboxes across.

Planning for Deployment

In this short series we’ll be focusing on the implementation and migration steps to move from Exchange 2010 to Exchange 2016, rather than implementing features like Database Availability Groups or configuring load balancing. Therefore, we’ll focus on a smaller organization with a relatively simple deployment.

Before you begin it’s important to understand that a key architectural change has been made in Exchange 2016. Exchange 2010 had a number of separate roles; Client Access, Hub Transport, Mailbox and Unified Messaging.

In Exchange 2016 only a single role is used, the Mailbox role. This contains all necessary components required.

Our example organization is Goodman Industries, who have a single Exchange 2010 multi-role server and will migrate over to a single Exchange 2016 mailbox server.

Figure 1: An overview of our topology

In the example above, you’ll see our source server EX1401 running Exchange 2010. Our target server will be EX1601. In a larger organization this would most likely be highly available, so we’d have multiple domain controllers (rather than just AD01) and use Database Availability Groups on the source and target.

Naming and Services

Our first step is to define names used by clients to access Exchange. Co-existence with Exchange 2010, 2013 and 2016 allows sharing of the same HTTPS names for Autodiscover, OWA, ActiveSync and other services, making it easy to transition across and reduce the risk of implementing co-existence.

Old Exchange 2010 Namespaces New Exchange 2016 Namespaces




Table 1

Exchange Server Sizing

The environment we’ll be implementing Exchange 2016 on is virtualised, running Hyper-V in our example.

CPUs Cores SPECint_rate2006   score Host RAM Disks   Available
2 x Intel Xeon 12 367 256GB 24 x 4TB 3.5” 7.2K RPM SAS (RAID 10)

Table 2

We have also collected statistics from the existing environment:

Number of mailboxes Average Message Size Average Received Average Sent Average Mailbox Size
150 75KB 30 15 1GB

Table 3

To calculate the requirements, we’ll use version 7.8 or higher of the Exchange Server Role Requirements Calculator. This supports both Exchange 2013 and Exchange 2016, so be sure to select the correct version when using the tool.

When sizing the solution two important factors will form design constraints:

  • The solution will not have high availability and instead will use Hyper-V for high availability.
  • The Exchange 2016 environment will provide quota limits of 5GB per user.
  • We’ll configure the maximum number of databases to be 5.
  • We’ll use a VSS-based backup solution rather than Exchange Native Protection – simply because it’s a non-HA simple environment.

Our output from the role requirements calculator results in the following server specification:

Hostname Virtual CPU RAM OS Disk Page file Disk Physical disks required Database virtual disks Log virtual disks Restore LUN
EX1601 1 x vCPU 16GB 100GB 20GB 4 x 4TB 5 x 291GB 5 x 5GB 1 x 213GB

Table 4

The Virtual CPU specifies how many CPU cores should be assigned to the Virtual Machine used, as does the RAM. The OS disk will hold both Operating System Exchange install and transport databases.

The Physical Disks represents how many of the available physical disks are needed to actually support the deployment and meet requirements for performance and space. In the virtual environment, these will be presented as virtual disks and will be used for database and log files respectively.

You’ll note that we’re still splitting databases and logs. For an implementation making use of Exchange Native Protection we wouldn’t look to do this, but for an implementation in a virtual environment that takes advantage of backups this is still required. We’ve also included an additional virtual disk to use as a restore LUN.

Splitting Databases from logs ensure that in the scenario of a log disk filling up, databases will not be corrupted. We also ensure that losing or the corruption of a virtual disk doesn’t result in a full restore of Exchange.

Updating the environment

Updating Exchange Server 2010

The minimum supported patch level for Exchange Server 2010 is Service Pack three with Update Rollup 11.

Exchange 2010 Service Pack 3 is available here.

Exchange 2010 SP3 Update Rollup 11 is available here. Install it, or a newer version if it is available.

Directory Service Requirements

The last few versions of Exchange had reasonably light requirements on AD functional levels. Now Windows 2003 R2 has finally went out of support the minimum Forest Functional Level and Domain Functional Level has been changed from 2003 and above. The minimum support FFL/DFL is now a minimum of Windows 2008 or above.

Updating Outlook Clients

Exchange 2016 supports Outlook 2010 and above on Windows, and on the Mac Outlook 2011 and higher. Outlook 2007 is no longer supported, but may work.

All versions of Outlook 2016 and Outlook 2013 are supported. Outlook 2010 is supported with the April 2015 update (KB2965295).

Update clients to the minimum supported version required before implementing Exchange 2016. Newer versions of Outlook will work with Exchange 2010 without issue.

Preparing the server for Exchange 2016

Exchange 2016 supports Windows 2012 and Windows 2012 R2. In our series we’ll use Windows 2012 R2.

We’ll be using physical disks to support Exchange 2016 and then creating virtual disks atop our Hyper-V environment. In Hyper-V, our new VM looks like this:

Figure 2: Hyper-V Configuration for our Virtual Machine

We’ll then proceed and install Windows Server 2012 R2 on the virtual machine used for Exchange 2016, then configure it with correct network settings, install the latest Windows updates and join it to our domain.

Storage Overview

Exchange Server 2016 supports NTFS and ReFS for Exchange databases and log files, and supports NTFS for operating system and Exchange binaries.

ReFS is recommended, with data integrity features switched off; therefore, we’ll format all Exchange database and log disks using this filesystem.

In addition to making sure we’re using the recommended filesystem, we will create mount points to represent the disks and their purpose:

Disk Mount Point
Page file E:
Database 1 C:\ExchangeDatabases\DB01
Database 2 C:\ExchangeDatabases\DB02
Database 3 C:\ExchangeDatabases\DB03
Database 4 C:\ExchangeDatabases\DB04
Database 1 Log C:\ExchangeDatabases\DB01_Log
Database 2 Log C:\ExchangeDatabases\DB02_Log
Database 3 Log C:\ExchangeDatabases\DB03_Log
Database 4 Log C:\ExchangeDatabases\DB04_Log
Restore LUN C:\ExchangeDatabases\Restore

Table 5

Initializing Disks

We will then bring storage online, initialize and then format and mount the storage. Launch Disk Management by right-clicking the Start Button:

Figure 3: Opening Disk Management

Within Server Manager, navigate to Disk Management. We will see in the upper panel the system disk, C: and the System Reserved Partition. These also display in the lower page, contained as partitions within the primary disk.

All newly added disks will typically be shown as offline. We’ll need to first change each of these disks to an online state before we prepare them. This is accomplished by right clicking each disk and simply choosing online. Perform this step, as shown below, across all new disks before proceeding:

Figure 4: Using Disk Management to bring a disk online

After bringing the disks online, we will now select one of the disks, right click and choose Initialize Disk:

Figure 5: Initializing disks for Exchange use

This will allow us to initialize all new disks in a single operation. We’ll ensure all disks are selected (in our case all 12 additional disks), then select GPT (GUID Partition Table), which is recommended for Exchange and supports disk sizes over 2TB, should they be required:

Figure 6: Selecting the GPT partition type


In part one of this series we have planned our simple deployment, ensured our Exchange environment and clients are up to date and started the preparation of the virtual machine for Exchange 2016. In the next part of this series, we will complete the virtual machine configuration and install Exchange 2016.

If you would like to read the other parts in this article series please go to:

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4 thoughts on “Migrating a small organization from Exchange 2010 to Exchange 2016 (Part 1)”

  1. I am performing a migration from exchange 2010, on an SBS server, to exchange 2016. I would like to use a different client access URL from the new server, the old uses office.domain.com but this is also being used for SharePoint. I would like the new server to use mail.domain.com. What steps will change for this walk though?

    Thank you,

  2. Hey Steve, great article. Thank you. Could you help me understand why you’ve gone with mount points in this walkthrough instead of having each volume be assigned a drive letter? Is that a requirement of the ReFS file system?

    Also, if you were to deploy the new Exchange 2016 server in a separate site.. The goal being to decommission Exchange 2010 from the previous AD site when complete.. Would it significantly change the process? My thought was that the external service URLs could be removed from the Exchange 2010 server and the new server in the new site could handle all mail in/out traffic until the migration was completed. Perhaps the internal service URLs on the Exchange 2010 server would need to be updated too.

  3. Hi
    Is it possible to migrate directly from UM in exchange 2010 sp3 to UM Service in exchange 2016?
    Or first, I have to migrate to Unified Messaging in exchange 2013 then migrating to exchange 2016?


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