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Deploying Microsoft SQL Server 2008 based Decision Support Systems using Dell EqualLogic 10GbE iSCSI Storage 13
running Quest Benchmark Factory for Databases and the monitoring system running SAN HQ to the
database server via the server LAN.
It is a best practice to provision the quantity and connection speed of the SAN NIC ports on your
server based on the throughput requirements of the workload.
4.4 Operating System Configuration
You should consider the following best practices for operating system settings in a DSS solution.
4.4.1 DiskPartitionsShouldbeAlignedWithStorageStripeBoundaries
You can enhance performance by ensuring alignment of file system partitions with the external
storage striping scheme. In an optimal configuration your partition boundaries will align with the RAID
striping scheme at block size multiples to minimize I/O operations. If partitions do not align with the
RAID striping scheme (i.e. block size) then the system will generate more I/O operations than in an
optimal configuration.
Windows Server® 2008 by default aligns partitions with an offset of 1024KB and thus accommodates
all RAID stripe sizes up to 1024KB. This default alignment is sufficient for creating partitions on
volumes hosted on EqualLogic Storage. Prior to Windows® 2008 the best practice is to manually align
the data partitions with an offset suitable to the RAID stripe size. This can be done using a utility such
as diskpart.exe.
4.4.2 NICDriverSettings
Jumbo frames provide a more efficient transport for the large data transfers typically generated by DSS
workloads. Flow control increases the ability of the NIC to regulate packet flow between the NIC and
the switch ports during high I/O traffic conditions.
It is a best practice to enable flow control (TX and RX) and jumbo frames on the Server NIC ports used
for connecting to the SAN and match these settings with the switch and array controller port settings.
UtilizeOffloadEngineCapabilitiesinYourNICs
We configured the BroadCom 57710 NIC ports on the database server to operate in the TCP offload
Engine (ToE) mode. For optimal performance with SQL DSS workloads you can enable ToE mode on
the NIC to work in conjunction with the Microsoft® iSCSI software initiator, Windows® MPIO, and the
Dell EqualLogic Multipath Device Specific Module (DSM) for MPIO.
The ToE mode can be enabled for the Broadcom NICs using the Broadcom Advanced Control Suite
(BACS) application. Ensure that ToE and the NDIS (Network Driver Interface Specification) options are
enabled on the iSCSI NIC ports. Disable iSCSI offload mode if ToE and NDIS are enabled on the same
port. ToE mode will need to be enabled in the operating system before you enable it in BACS.
Note: We recommend that you review the information provided by Microsoft in following
paper: “Microsoft SQL Server 2008: Disk Partition Alignment Best Practices for SQL
Server”, available at the following location:
http://msdn.microsoft.com/en-us/library/dd758814.aspx
.