Selecting a storage controller

You should be on the VMware VSAN Compatibility Guide page.

The initial landing page for the VSAN Compatibility Guide will allow you to browse through VSAN Ready Node configurations. As we will be discussing the case of VSAN Ready Nodes later in this chapter, for now please click the "Build Your Own based on Certified Components" link from the main page of the VSAN Compatibility Guide:

Unlike the regular VMware Compatibility Guide, the VSAN-specific component guide is laid out as a branching tree that you can use to drill down to your desired configuration, after which time hardware choices will be displayed.

After making your selections, choose Update and View Results to get a list of hardware that matches your specifications.

Aside from simply ensuring that you select a supported storage controller, the VSAN-specific Compatibility Guide also provides you with additional detail that will be crucial to selecting your storage controller.

This view will tell you whether or not the controller supports the pass-through/JBOD mode and, vitally, it will tell you the controller's command queue depth. The controller's queue depth is a vital consideration. If each node is relatively small with one disk group, any queue depth above 256 commands is acceptable. If you have two disk groups, please consider 512 commands to be the minimum queue depth.

For large or high-performance configurations with several disk groups and extremely large capacities, and/or very high-performance SSDs, you should choose the highest queue depth you can. Standard controllers with maximum queue depths usually have around 1000 commands, like in the preceding example.

Queue depth can have a tremendous effect on the performance of streaming data. Opting for controllers and disks with deeper queues will provide better overall performance, particularly when VSAN is reconfiguring or resynchronizing data.