We announced the depreciation of vFlash Read Cache (vFRC) in the release notes of vSphere 6.7 Update 2. vFRC continues to be supported for vSphere 6.0/6.5/6.7. However, the next major release will not.
VMware vSphere Flash Read Cache is being deprecated. While this feature continues to be supported in the vSphere 6.7 generation, it will be discontinued in a future vSphere release.
The rationale behind the deprecation is that we have a very small customer-base using the feature, while the feature is not a core investment future focus area. When we talk about accelerating storage performance, or enhancing the overall datacenter storage experience, the focus is on VMware vSAN.
What is vFRC?
vFRC is a Hypervisor-based caching solution feature introduced with vSphere 5.5. It pools multiple flash devices as a resource and is part of the vSphere and vSOM Enterprise Plus bundle. The goal of vFRC feature is to enhance performance of certain I/O workloads that exhibit characteristics suitable for caching. vFRC uses local flash media to create a cache repository for read I/Os.
vSphere administrators can configure virtual machines to use a specific amount of vFRC space. Do note that vFRC is used on a ‘per virtual disk’ basis. That means you can have a specific virtual machine with multiple virtual disks in it, you have the option to accelerate specific virtual disks. Visit this blog article for more technical details on vFRC.
Customer that are using VMware vSAN will automatically benefit from its architecture that consists of a cache and capacity storage layer. When there is need for a caching mechanism to accelerate storage arrays, customers have alternative options as the release notes also states.
As an alternative, you can use the vSAN caching mechanism or any VMware certified third-party I/O acceleration software listed in the VMware Compatibility Guide.