Occasionally, I will have a technical conversation with a customer on IOPS limit so rather than repeating myself, I thought I should document it here for everyone’s benefit. Cormac Hogan had written up a good introduction to vSAN IOPS Limit storage policy that was introduced back in vSAN 6.2.
Beyond, the feature, I thought I should illustrate IOPS limit in action and highlight use cases when you would potentially want to use it.
When designing a vSAN host, one of the consideration to increase availability is by having multiple disk groups and multiple IO controllers within a host. The obvious benefit to this would be to reduce the impact in when a disk or IO controller fails.
When a decision is made to use multiple IO controllers to drive disk groups within a vSAN host, it is important that the failure domain of such configuration is aligned with the physical setup.
Every so often, I will see someone hitting a speed bump setting up a disk group for vSAN. The case is the same when setting up for build your own vSAN using the disk claim wizard or VMware Cloud Foundation bring up. I thought I would do a quick write up to set it straight and point out some things to watch out for and different ways to overcome this.
