Tuning SQL Server 2005 on Windows Integrity Servers

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value to a number greater than or equal to the number of spindles. Emulex driver options set in
HBanyware utility should be greater than or equal to the number of physical drives (default = 20).
When using the Qlogic HBA, use the SanSurfer utility. Use this utility to change the Qlogic firmware
BIOS setting for execution throttle in NVRAM can be changed using the SanSurfer utility to be equal
to or greater than the number of physical drives (default = 16).
For maximum I/O performance, QLogic HBA with the QLDirect Optimizing & Multipath Driver uses
less CPU than Miniport drivers. (CPU utilization is 50+% less with Qlogic/QLDirect compared to
Miniport drivers.)
Verify the port speed on the switch is set to the maximum
Use the diagnostic LEDs to make sure that the switch is operating at it’s maximum speed. To set the
port speed on a Broadcom switch:
Access the switch using its IP address via telnet or web browser. Autosense for HBAs should set the
speed to 2 Gb.
To manually configure the speed of a port to 2 Gb, use the portcfgspeed command as follows:
Switch:admin> portcfgspeed port [speed]
The speed parameter is defined as: 0 = AN (auto negotiate); 1 = 1 Gb or ; 2 = 2 Gb
On Qlogic switches, Auto Sense is the default. To set it as above, use the SanSurfer Switch Manager
utility.
Network
SQL network traffic packets are typically small so the maximum achievable bandwidth of a network
link can not be fully utilized. We recommend that you not exceed 15,000 packets per second on a
Gigabit link. NIC teaming is an option, but does require additional overhead that could affect
performance.
Intel NICs are usually faster than Broadcom NICs because of lower CPU load.
Enable options to offload processing
Checksum offloads, TCP segmentation (Large Send), and Interrupt Coalescing all serve to minimize
CPU utilization and improve network throughput.
Verify that the network adapter’s advanced property for "CHECKSUM OFFLOAD" is enabled for
Transmit/Receive TCP/IP. To verify the checksum value:
1. Open the properties for the network adapter on the server.
2. Verify the advanced setting for "CHECKSUM OFFLOAD" is set to "Tx/Rx TCP/IP
Checksum".
3. If you modify the setting, you must reboot the server.
On the Gigabit Ethernet NIC Driver, Coalescing is enabled by default. Coalesce Buffers are used to
copy fragments of a transmit packet into before assigning them a transmit descriptor. This reduces the
number of transmit descriptors required for each packet transmission.
For Intel NIC drivers, set the Interrupt Moderation Rate to high or extreme.