Steven,  You don't need a direct correlation between front-end path/port count and meta member count; I was just pointing out that these two variables have a multiplying effect when it comes to the number of concurrent queues available for a particular host's workload. For example, if you have an 8-way striped meta mapped through four FA ports, then there are 4*8=32 queues that can concurrently service the workload on that meta.  The RR change from 1000 to 1 is also related to optimal use of these queues. With the default of 1000, the ESX NMP policy will send a stream of 1000 IOs to one FA port before switching paths -- the other FA paths, which have their own discrete CPU cores and queues on the VMAX, will be sitting idle while ESX directs all IO to a single path. This can result in longer queues on the currently active path, which in turn results in elongated response time (the deeper the queue, the higher the response time). By setting RR to 1, ESX switches to a different path for each IO, so the IO is balanced across all VMAX front-end CPU cores and queues.  You can think of a queue as being like a teller line at a bank -- in a particular line/queue, only one person is being serviced at a time. The time it takes for the "active" person's service to complete is called the Service Time. Response Time is the perceived amount of time it takes for a new person (or IO) to be serviced, starting at the time they enter back of the line. Response Time is the Service Time (amount of time it takes to complete one order/IO) multiplied by the queue depth (how many people are in front of you waiting to be serviced). Ideally you want to distribute your workload evenly among many queues, so the lines are short and response times are kept low.  Hope that helps,  - Sean
When creating a meta volume you have the option to pick your:  "Meta Volume Member Count Including Head"  We have 24 disks in our SAS pool as you can tell from the screen shot. I see that 64 meta volumes is recommended and that I can actually select more meta volumes than I have actual disks.  Is there actually any performance benefits to adding more meta volumes than there are actual disks? You're still limited by spindles.  Thank you kindly, Steven
Benefit of Meta Volume Member Count (greater than disk count)