Follow these Dell EMC-recommended practices for configuring the servers:
- Use the latest BIOS and firmware for the PowerEdge servers.
- Use the latest vendor-subscribed HBA drivers.
- Enable Intel Hyper-Threading, which enables higher utilization of the available physical cores to deliver the best SQL Server performance from the compute resources.
- Configure the power plan as follows:
i Go to System Setup > System BIOS > System Profile Settings, and select Performance Per Watt Optimized (DAPC) from the list.
ii Go to System Setup > System BIOS > Processor Settings > Dell Controlled Turbo, and select Enabled.
- In the operating system: Go to Control Panel > Power Plans Scheme, and select High Performance Plan.
This section outlines the best practices for configuring the network in the Ready Solution for SQL Server.
Best practices for configuring the LAN include:
- Use two 10 GbE S4048-ON network switches for end-to-end client traffic to prevent a single point of failure.
- Use VLAN tagging to sustain switch failure, and use NIC teaming to provide multitier network high availability.
- Use NIC teaming to provide high availability at the NIC port level.
- Use NIC teaming for virtual and physical network connections.
- Use a minimum of two network cards to provide high availability and prevent a single point of failure.
- Use two Intel Ethernet 10 GbE dual-port X710 adapter cards to enable connectivity between the SQL Server host and applications on the external network.
Best practices for designing the SAN include:
- Use redundant Connectrix 6610 switches to prevent a single point of failure.
- Use two Emulex LightPulse LPE31002 cards per server for high availability.
- Use named zoning of end devices (FC HBAs) and Dell EMC Storage Center virtual ports while creating zones. Named zoning provides better flexibility because it does not bind the devices and virtual ports to specific physical ports on either the switch or the storage array.
- Make crisscross cable connections between redundant FC HBA cards and redundant FC switches to enable high availability, as shown in the following figure.
Figure 3. Connections between PowerEdge R740 and Connectrix switches
Dell EMC Unisphere storage management is a web-based solution that provides an interface for storage management and configuration tasks. The configuration depends on performance and capacity needs, preferred type of server connectivity, performance in terms of IOPS and MB/s, and future growth needs for both performance and capacity. This section provides guidance and best practices for storage management and configuration.
Dell EMC recommends that you use fewer storage pools within Unity storage to reduce complexity and increase flexibility. However, you might want to configure multiple storage pools to do the following:
- Separate workloads with different I/O profiles.
- Dedicate resources to meet specific performance goals.
- Separate resources for multitenancy.
- Create smaller failure domains.
Storage pools must maintain free capacity to operate properly. By default, Unity storage raises an alert if a storage pool has less than 30 percent free capacity. It also automatically begins to invalidate snapshots and replication sessions if the storage pool has less than 5 percent free capacity. Dell EMC recommends that storage pools always have at least 10 percent free capacity.
Dell EMC storage systems use multiple drive types, with varying capacities and performance levels, and attempt to match data with the optimal drive type based on storage pools. Typically, mission-critical data is stored on high-performance drives, while less-critical data is moved to high-capacity drives.
While every environment is unique, an OLTP workload generally consists of small, random reads and writes. The required number of IOPS primarily determines the sizing of a storage system that services an OLTP workload. Different drive types have different performance capabilities. Faster-spinning drives can provide more IOPS with lower latency than slower-spinning drives. For best performance, Dell EMC recommends SSDs for OLTP workloads.
The following factors affect drive selection:
- Type of workload
- Expected IOPS, latency, and throughput
- Database size
You can calculate the number of required disks as follows, depending on the target IOPS requirements:
Number of disks = (Read IOPS + [Write IOPS x RAID performance overhead]) / IOPS per disk
I/O path settings
FC zoning enables the partitioning of the FC fabric into multiple subsets called zones. A zone includes FC initiators and targets, and enables communication between the initiators and targets.
Best practices for setting the I/O paths include:
- Single-initiator, multiple-target zoning—Creates each FC zone with a single initiator (HBA port) and multiple targets (front-end ports). Therefore, each HBA port requires a separate FC zone with front-end ports. Create independent zones for each HBA that is installed in the host.
- World Wide Name (WWN) zoning—Contains only the host HBA port and the front‑end primary ports. In most cases, including the front-end reserve ports is unnecessary because they are not used for volume mapping. Dell EMC recommends creating zones by using a single initiator host port and multiple Storage Center ports.
- Multipathing—Designates how many of the Dell EMC storage front-end ports that the system allows the volume to be mapped through. Dell EMC recommends the use of the Dell EMC PowerPath/VE Multipathing utility for designating the ports.
Create a server cluster for high availability and map the volumes to the server cluster. Map the volumes by using Storage Center Console or Enterprise Manager Console.
For optimal performance and better monitoring resolution, Dell EMC recommends that you:
- Place tempdb, data, and log files on separate LUNs.
- Leave room for data growth and avoid exceeding 80 percent capacity of the LUNs for database files.
- Configure end-to-end multipathing by using PowerPath/VE software for availability/redundancy and throughput optimization.
- Use multiples of 64 KB as allocation units for SQL Server volumes.
- Ensure that I/O is distributed across both controllers of the storage array. For best results, evenly distribute the heavy-I/O LUNs and try to use the same number of LUNs or volumes on each controller.
For ESXi storage design, Dell EMC recommends that you:
- Create a virtual SAN by grouping WWNs of virtual FC adapters that are hosted in PowerEdge servers and Dell EMC storage. Configure the VMs that are hosting SQL Server with direct access to the storage LUNs.
- Create a single large pool with RAID 10 configured, rather than many smaller pools.
- Use multiple LUNs or volumes for the database data files that have low latency and high IOPS requirements.
- Use PowerPath/VE software for multipathing.