Specifications

Best Practices for Virtualizing and Managing Exchange 2013

Best Practices and Recommendations

Fixed VHDs may be stored on SMB 3.0 files that are backed by block-level storage if the guest

machine is running on Windows Server 2012 Hyper-V (or a later version of Hyper-V). The only

supported usage of SMB 3.0 file shares is for storage of fixed VHDs. Such file shares cannot be

used for direct storage of Exchange data. When using SMB 3.0 file shares to store fixed VHDs,

configure the storage backing the file share for high availability to ensure the best possible

availability of the Exchange virtual machines.

SMB Multichannel

Both the SMB client and SMB server must support SMB 3.0 to take advantage of the SMB Multichannel

functionality. SMB Multichannel increases network performance and availability for file servers. SMB

Multichannel allows file servers to use multiple network connections simultaneously. This increases

throughput by transmitting more data using multiple connections for high-speed network adapters or

multiple network adapters. When using multiple network connections at the same time, the clients can

continue to work uninterrupted despite the loss of a network connection. SMB Multichannel automatically

discovers the existence of multiple available network paths and dynamically adds connections as required.

Best Practices and Recommendations

If you use SMB storage with Hyper-V, use multiple network adapters to take advantage of SMB

Multichannel, as this provides increased performance and resiliency.

SMB Direct (SMB over RDMA)

Windows Server 2012 introduces SMB Direct, a feature that provides the ability to use Remote Direct

Memory Access (RDMA) network interfaces for high throughput with low latency and CPU utilization. SMB

Direct supports the use of network adapters that have RDMA capability. Network adapters with RDMA can

function at full speed with very low latency, while using very little CPU. For workloads such as Hyper-V or

Exchange Server, this enables a remote file server to resemble local storage. SMB Direct is automatically

configured by Windows Server 2012 and includes the following benefits:

 Increased throughput: Takes advantage of the full throughput of high-speed networks where

the network adapters coordinate the transfer of large amounts of data at line speed.

 Low latency: Provides extremely fast responses to network requests and, as a result, makes

remote file storage feel as if it is directly attached block storage.

 Low CPU utilization: Uses fewer CPU cycles when transferring data over the network, which

leaves more power available to server applications.

By supporting mission-critical application workloads, the new SMB server and client cooperate to provide

transparent failover to an alternative cluster node for all SMB operations for planned moves and

unplanned failures. This results in reduced cost, improved high availability, and increased performance for

workloads in a virtualized environment.