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PowerStore presents storage to external hosts through either block or file interfaces. Block storage is the most commonly used datastore path for virtual machines due to the various speeds and protocols that are offered, making it ideal for performance. NFS is also used but is less common. PowerStore supports 25 GbE and 32 Gb FC connections for broad compatibility and performance requirements. Instructions and best practices for configuring hosts are in the Dell EMC PowerStore Host Configuration Guide on the PowerStore Info Hub.
Multipathing is critical to achieving the best performance from VMware hosts and should be configured properly. For configuration guidance, see the document Dell EMC PowerStore: VMware vSphere Best Practices on Dell.com/StorageResources. The large number of small I/Os generated from VDI environments benefit greatly from round robin and rapid path switching. Consider using and perform testing with a low I/O-per-path change, which can help improve VM performance.
The MPIO configuration used was Round Robin as shown:
This provides optimal pathing with failover protection and path discovery.
Using iSCSI for block storage allows convergence of storage and networking infrastructure though it does require careful planning for bandwidth requirements and fault isolation. Redundant networks are preferred for data availability.
With iSCSI, Jumbo frames are also highly recommended. They allow greater packet efficiency for higher bandwidth. Using Jumbo frames is not a requirement but should be considered. Combined with the 25 GbE connectivity available in PowerStore, iSCSI can handle demanding workloads and high throughput requirements. All devices in this configuration were configured for Jumbo frames. This reduces network switch loads as a smaller number of large packets are processed.
Another benefit of using the Ethernet infrastructure for iSCSI is the ability to share the network with file services. This use requires planning to ensure that there is enough bandwidth for all services, but it also reduces the hardware requirements. The use of different VLANs also allows traffic prioritization to ensure that block traffic has the highest priority.
The iSCSI traffic was configured for 9000-byte Jumbo frames over 8 x 25Gb Ethernet ports. The ports were configured in pairs across two I/O modules per node for complete redundancy and throughput. This also spreads the load across more I/O modules to improve packet performance.