Content Based Read Cache (CBRC) and VMware View 5.1

Implementing our VMware View 5.1 solution and enabled CBRC with 2048 MB for each host. This feature is used to provide memory based read cache for the more used portions of the vmdk.

When deploying the linked clone pool, there is a process that builds the virtual disk digest. This take a few minutes, as the replicas are building as well. As soon as those are built the deployment process is very quick. We are also using NetApp FlashCache with the deployment and I am not sure yet how that will work in, but as soon as we have all in place, we can look at some performance metrics.

Storage Optimization New in View 5.1, View Storage Accelerator is a technology that reduces storage loads generated by peak VDI storage reads caching the common blocks of desktop images into local host memory. The Accelerator leverages a VMware vSphere (version 5.0 or later) platform feature called Content Based Read Cache (CBRC) implemented inside the ESX/ESXi hypervisor. When enabled for specific VMs, the host hypervisor scans the storage disk blocks to generate digests of the block contents. When these blocks are read into the hypervisor, they are cached in the host based CBRC. Subsequent reads of blocks with the same digest will be served from the in-memory cache directly.  This significantly improves the desktop performance, especially during boot storms or anti-virus scanning storms when a large number of blocks with identical contents are read. “

Thanks to:

Dan Brinkmann’s blog

And a very detailed explanation, as well as how to configure vSphere 5 from virtually Ghetto

My Virtual Cloud