Design Considerations for Storage Controllers in vSAN

Include storage controllers on the hosts of a vSAN cluster that best satisfy the requirements for performance and availability.

• Use storage controller models, and driver and firmware versions that are listed in the VMware Compatibility Guide. Search for vSAN in the VMware Compatibility Guide.
• Use multiple storage controllers, if possible, to improve performance and to isolate a potential controller failure to only a subset of disk groups.
• Use storage controllers that have the highest queue depths in the VMware Compatibility Guide. Using controllers with high queue depth improves performance. For example, when vSAN is rebuilding components after a failure or when a host enters maintenance mode.
• Use storage controllers in passthrough mode for best performance of vSAN. Storage controllers in RAID 0 mode require higher configuration and maintenance efforts compared to storage controllers in passthrough mode.
• Disable caching on the controller, or set caching to 100 percent Read.