White Papers

Windows setup and configuration
17 Dell EMC SC Series: Microsoft SQL Server Best Practices | CML1057
5 Windows setup and configuration
5.1 Allocation unit size
Use a 64 KB allocation unit size when formatting volumes that will contain database files (transaction log and
data) or database backups.
5.2 MPIO
Set the MPIO policy to Round Robin for all database volumes. This is the default for Windows Server 2008
and newer. It allows all paths to be used, enabling higher throughput between the server and the array. This
setting works best for most environments as it is easy to manage and performs very well.
For database servers with a large number of I/O ports, the overhead of the Round Robin MPIO policy can
reduce the maximum throughput to the storage array. To maximize throughput, create a volume for each port
on the server and use the Fail Over Only MPIO policy to define a single, unique, active path for each volume.
All other paths should be defined as standby paths. By using a data file of the same size on each volume, the
data will be evenly distributed across the volumes. This strategy is more complex to setup and maintain. It
should only be used in environments that require maximum throughput.
5.3 Partition alignment
An offset of 64 KB, or a multiple of 64 KB, is recommended for volumes created on Windows Server 2003 and
earlier. New volumes created on Windows Server 2008 or newer should already be aligned since 1024 KB is
the default offset.