Storage IO path in VSAN and VirtuCache is similar to a large extent since both service storage IO from in-VMware host media. Though with VirtuCache, storage latency is lower than with VSAN for four reasons: Reads are always serviced from local cache media in VirtuCache. In VSAN there is a…
If you are experiencing storage performance issues, and if you have greater than 30 Datastores in an ESXi cluster, then this most likely is the cause of your storage performance issues, even if you have a high performing all-flash array and a high speed storage network. First we start with…
One advantage that Hyper-converged infrastructure(HCI) has over SAN infrastructure is that HCI has put high speed storage back in the hosts. This is also true for Host Side Caching software. However, unlike HCI, host side caching retains the flexibility that SAN infrastructure has over HCI, of being able to do…
In terms of price/performance, enterprise NVME SSDs are the best choice for in-VMware host caching media. The Samsung PM1735 (in PCIe form factor) and the Micron 9400 Max (2.5″ U.x form factor) NVME SSDs are my favorites. If you don’t have a spare U.x NVME slot or a conventional PCIe…
There are some applications, typically desktop and SMB CAD/CAM, Manufacturing, ERP software that require large amounts of IOs per second (greater than 10,000) at small queue depth (less than 8). For a primer on how Queue Depths affect Latency and IOPS, review this post , which defines various types of…

