The Storage Heavy Hitters dashboard forms a pair with the Network Top Talkers dashboard. To understand the IO demands in your environment, use both of them together. If you are using ethernet-based storage, storage traffic runs over the same physical network as your ethernet-based network traffic.

Design Considerations

The Storage Heavy Hitters dashboard forms a pair with the Network Top Talkers dashboard, so they share a consideration behind their design. For more information, see Network Top Talkers Dashboard.

How to Use the Dashboard

  • See the Network Top Talkers dashboard as they have the same design.
    • The main difference between Storage Heavy Hitters and Network Top Talkers is that the storage IO has two dimensions: IOPS and throughput.
    • Network IO does not have the IOPS dimension as the packet size is identical (1500 bytes being the standard packet, and 9000 bytes being the jumbo frames).
    • Storage IOPs and throughput are related, so use both to gain insight, they should display a similar pattern. If not, that indicates varying block sizes. For example, a throughput spike without an accompanying IOPs spike indicates large block sizes.
  • Which VMs hit the storage the hardest.
    • The table shows the most demanding VM. You can identify the villain VM and compare their demands with the capabilities of the underlying IaaS. Knowing the infrastructure capability is important, because different classes of SSD have different IOPS and throughput capabilities.

      After identifying the villain VM, talk to the VM owners if the numbers are excessive during peak hours and identify the reasons behind the excessive usage. You must ensure that they do not create a hot spot. For example, vSAN cluster with > 100 disk can handle numerous IOPS but if the VM objects are only on a few disks, those disks can become a hot spot.

Points to Note

  • Interpreting IOPs and throughput metrics depends on your underlying physical storage. For visibility into this hardware layer, add physical storage metrics to the dashboard.