Exchange System: Lesson 2 Exchange Server 2013 Prerequisites and Requirements
Please read Exchange lesson 1 first
DNS Server Requirements for Exchange Server 2013
Each computer that is running Exchange Server must use DNS to locate AD DS and the global catalog servers. As a site-aware application, Exchange Server 2013 prefers to communicate with domain controllers that are located in the same site as the computer that is running Exchange Server. Exchange Server services use DNS to locate a valid
domain controller or global catalog. By default, each time a domain controller starts the Netlogon service, it updates Domain Name System(DNS) with service (SRV) records that describe the server
as a domain controller and global catalog server, if applicable. To ensure that the domain controller updates DNS records properly, it is essential that all domain controllers use an internal DNS server that supports dynamic updates. After DNS records are registered, computers that are running Exchange Server can use DNS to find domain controllers and global catalog servers.
SRV Resource Records
SRV resource records are DNS records that identify servers that provide specific services on the network.
For example, an SRV resource record can contain information to help clients locate a domain controller in
a specific domain or site.
All SRV resource records use a standard format, which consists of several fields that contain information
that AD DS uses to map a service back to the computer that provides the service. The SRV records for
domain controllers and global catalog servers are registered with different variations to allow locating
domain controllers and global catalog servers in several different ways.
One option is to register DNS records by site name, which enables computers that are running Exchange
Server to find domain controllers and global catalog servers in the local Active Directory site. Exchange
Server always performs DNS resource queries for the local Active Directory site first.
When a computer that is running Exchange Server is a member server, Exchange Server configures it
dynamically with its site each time it authenticates to AD DS. As part of the authentication process, the
registry stores the site name. When the Exchange Server queries DNS for domain controller or global
catalog server records, the Exchange Server always attempts to connect to domain controllers that have
the same site attribute as the Exchange Server.
Host records provide host name to IP address mapping. Host records are required for each domain
controller and other hosts that need to be accessible to Exchange Servers or client computers. Host
records can use Internet Protocol version 4 (IPv4), which are A records; or Internet Protocol version 6
(IPv6) records, which are AAAA records.
A Mail Exchanger (MX) record is a resource record that allows servers to locate other servers to deliver
Internet email by using the Simple Mail Transfer Protocol (SMTP). An MX record identifies the SMTP server
that will accept inbound messages for a specific DNS domain. Each MX record contains a host name and a
preference value. When you deploy multiple SMTP servers that are accessible from the Internet, you can
assign equal preference values to each MX record to enable load balancing between the SMTP servers.
You also can specify a lower preference value for one of the MX records. All messages are routed through
the SMTP server that has the lower preference value MX record, unless that server is not available.
Note: In addition to SRV, Host, and MX records, you also might need to configure
Sender Policy Framework (SPF) records to support Sender ID spam filtering. In addition, some
organizations use reverse lookups as an option for spam filtering, so you should consider adding
reverse lookup records for all SMTP servers that send your organization’s email.
Software Requirements for Exchange Server 2013
Exchange Server 2013 requires that some software be preinstalled before you start the deployment
process. First, you should plan for the operating system platforms that will be used for Exchange Server 2013. The following operating systems are supported for installation of Exchange Server 2013
• Windows Server® 2012 Standard or
• Windows Server 2008 R2 Standard with
Service Pack 1 (SP1)
• Windows Server 2008 R2 Enterprise with SP1
• Windows Server 2008 R2 Datacenter RTM or newer
Note: Server Core installation option is not a supported operating system option for
Exchange Server 2013 installation. In addition, Windows Server 2008 R2 Standard does not
support failover clustering and cannot use database availability groups (DAGs) in Exchange Server
for high availability. You cannot upgrade Windows Server after you have installed Exchange.
Depending on which Exchange Server role is installed, different Windows components can be installed on
a server. However, you do not need to install these roles and features prior to Exchange Server installation
because the installation process can install the necessary roles and features automatically.
Note: If you choose to install Windows Server roles and features during Exchange Server
setup, you might be required to restart the server before Exchange server starts installation. This
is expected behavior.
However, there are additional components that you should install manually. These components, freely
available to download from Microsoft, include:
• Microsoft .NET Framework 4.5 (only for Windows Server 2008 and 2008 R2).
• Windows Management Framework 3.0 (already included with Windows Server 2012).
• Remote Server Administration Tools (RSAT) for AD DS (can be installed with Server Manager).
• Microsoft Unified Communications Managed API 4.0, Core Runtime 64-bit.
• Microsoft Office 2010 Filter Pack SP1 64-bit or Microsoft Office 2013 Filter Pack.
• Exchange Server Updates for Knowledge Base articles KB974405, KB2619234, and KB2533623 when
installing Exchange Server 2013 on Windows Server 2008 R2.
You also should ensure that the Task Scheduler service is enabled and running on the server where you
plan to install Exchange Server 2013.
Hardware Requirements for Exchange Server 2013
Determining the hardware requirements for Exchange Server 2013 is more complex than simply reading the specifications provided byMicrosoft. Many other factors can influence the Exchange Server hardware design, aside from the general specifications that provide information about minimum supported hardware configuration.
First, the server role that is installed has asignificant influence on hardware specifications.
For example, the Mailbox server likely requires more powerful hardware than the Client Access
server does. Second, many organizations install all Exchange Server roles on a single computer, which
means that you must merge hardware requirements for each of the roles.The processor for an Exchange Server computer must be a 64-bit architecture-based Intel® processor that supports Intel 64 architecture (formerly known as Intel EM64T), or an AMD processor that supports the AMD64 platform. Intel Itanium IA64 processors are not supported.
We recommend that you consider using the maximum server memory configuration when deciding on
the amount of RAM memory that you need for Exchange Server 2013. Different server architectures have
different memory limits. Check the following technical specifications for the server to determine the most
cost-efficient maximum memory configuration:
• Memory speed. Some server architectures require slower memory modules to scale to the maximum
supported amount of memory for a specific server. For example, the maximum server memory might
be limited to 32 gigabytes (GB) with PC3 10666 (DDR3 1333), or 128 GB using PC2 6400 (DDR2 800).
Check with the manufacturer to ensure that the memory configuration target for Exchange Server
2013 is compatible in terms of speed.
• Memory module size. Consider choosing the largest memory module size that the server supports.
Generally, the larger the memory module, the more expensive it is. Make sure that the maximum
memory module size allows you to meet your target memory requirements for Exchange Server 2013.
• Total number of memory slots. Consider how many memory modules a specific server will support.
The total number of slots, multiplied by the maximum memory module size, provides the maximum
memory configuration for the server. Keep in mind that memory modules sometimes must be
installed in pairs.
When you plan the amount of memory to be installed in Exchange servers, you should follow these
• Mailbox: 8 GB minimum
• Client Access: 4 GB minimum
• Mailbox and Client Access combined: 8 GB minimum
Some servers experience a performance improvement when more memory slots are filled, while others
experience a reduction in performance. Check with your hardware vendor to understand this effect on
your server architecture.
Disk Drive Space
You have to consider several requirements when choosing and configuring disk drives for an Exchange
Server 2013 installation. You must have:
• At least 30 GB on the drive on which you install Exchange.
• An additional 500 MB of available disk space for each Unified Messaging (UM) language pack that
you plan to install.
• 200 MB of available disk space on the system drive.
• A hard disk that stores the message queue database on with at least 500 MB of free space.
• All partitions that Exchange Server 2013 will use must be formatted with the NTFS file system.
The space required for the Mailbox server role cannot be determined without knowing the number of
mailboxes, mailbox sizes, and high-availability requirements, among other parameters. We recommend
that you use the Mailbox server role calculator to determine optimal hardware requirements for the
Mailbox server role.
Hardware Configuration for Servers with Multiple Server Roles
When you design the hardware configuration for servers on which you install multiple server roles,
consider the following recommendations:
• Plan for a minimum of two processor cores. The recommended number of processor cores is eight,
while 24 is the maximum recommended number.
• Design a server with multiple server roles to use half of the available processor cores for the Mailbox
server role, and the other half for the Client Access server role.
• Plan for the following memory configuration for a server with multiple server roles: 8 GB, and
between 2 MB and 10 MB per mailbox. This can vary based on the user profile and the number of
mailbox databases. We recommend 64 GB as the maximum amount of memory that you need.
• Reduce by 20 percent the number of mailboxes per core calculation, based on the average client
profile, to accommodate the Client Access server role on the same server as the Mailbox server role.
• Deploy multiple Exchange Server roles on a Mailbox server that is a DAG member, if desired. This
scenario provides full redundancy for the Mailbox and the Client Access server roles on just two Exchange 2013 servers.
Infrastructure Requirements for Exchange Server 2013
Before you deploy Exchange Server 2013 in your organization, you need to ensure that your organization meets AD DS and DNS requirements.
AD DS Requirements
You must meet the following AD DS requirements before you can install Exchange Server 2013:
• The domain controller that is the schema master must have Windows Server 2012, Windows Server 2008 R2, Windows Server 2008, or Windows Server 2003 with Service Pack 2 (SP2). By default, the schema master
runs on the first Windows domain controller installed in a forest.
• In each of the sites where you deploy Exchange Server 2013, at least one global catalog server must
be installed and must run Windows Server 2012, Windows Server 2008, Windows Server 2008 R2, or
Windows Server 2003 SP2.
• In each site where you plan to install Exchange Server 2013, you must have at least one writable
domain controller running Windows Server 2012, Windows Server 2008, or Windows Server 2008 R2.
• The Active Directory domain and forest functional levels must run Windows Server 2003, at the
minimum, or newer versions.
Before you install Exchange Server 2013, you must configure DNS correctly in your Active Directory forest.
All servers that run Exchange Server 2013 must be able to locate Active Directory domain controllers,
global catalog servers, and other Exchange Servers.