This post is going to give an overview about new functionality called Flash Read Cache released as part of VMware vSphere 5.5. This functionality helps VMware ESXi host to leverage the flash storage devices.  This feature allows you to use SSD ( such as PCIe flash cards and SAS/SATA SSD drives) as a storage read cache. This will provide the better performance on many workloads as to caching the data on the ESXi host in super fast flash memory. This gives greater throughput and low latency.

Most of the vSphere features such as vMotion,DRS and HA can be continued used while using Flash Read Cache. Each ESXi host can have upto 8 SSDs. SSD is nothing but Solid State Drive, 4TB of capacity each with the maximum of 32 TB supported of now.

vSphere Flash Read Cache (vFRC)  utilizes the vSphere Flash Infrastructure layer to provide a host-level caching functionality for virtual machine I/Os using flash storage. The goal of introducing the vFRC feature is to enhance performance of certain I/O workloads that exhibit characteristics suitable for
caching.

The flash resource created using vSphere Flash can be used for the below two purposes

1 Read Caching of Virtual Machine I/O requests (vSphere Flash Read Cache)
2  Storing the Host Swap file.

Excellent Video Created By Jason Nash “Demo of vSphere 5.5’s New Flash Read Cache”

 Will Talk more about vSphere 5.5 features in upcoming posts. I believe this is informative for you. Thanks for Reading.