With VSAN 6.2 VMware added a lot of new features, like dedup, compression and checksums. Some of these features can use CPU resources to a certain extent – depending on your workload.

In my personal experience with customers, I have found that the Checksum option can produce some overhead – especially in All-Flash configurations with extremly high IO, or if you are doing benchmarks (which also produces high IO load normally…)

If you are using all-SSD configuration and you can live without checksums, just change your VSAN policies accordingly. Use the “Disable object checksum” option in your storage policy and set the option to “YES”.

Here is the link to VMware’s VSAN documentation.

Are you using a Hybrid VSAN 6.2 configuration?

There is another hint for you. Since VSAN 6.2 VSAN is always calculation Deduplication / Compression data. – WHich in case of Hybrid configuration deos not make any sense at all. – But it produces a certain overhead.

There is a very important Knowledge Base article for you if you are using VSAN in hybrid mode. – Change some options and get better performance!

http://kb.vmware.com/kb/2146267