EMC has recently conducted some VMware View 5.1 validation tests with their VSPEX pre-validated architecture. As part of the validation tests EMC also captured some awesome performance data where we can clearly see the benefits delivered by the new View Storage Accelerator feature.
The data has been collected as NFS reads/sec measured at the hypervisor layer for approximately 143 linked clone desktops running in a single physical host.
CBRC was configured with 2GB cache, and only the replica disk has been digested. CBRC also allow digest creation for linked clone and persistent disks, but it was not enabled for this validation.
EMC found three scenarios where CBRC provides most performance benefits. This first scenario is comparing a 90 minutes logon storm being generated by Login VSI, with and without CBRC. Almost all reads are served from the CBRC cache.
After the logon storm Login VSI starts a mixed steady-state workload that involves write intensive operations. CBRC is a read-only caching technique and won’t help with write intensive workloads. For write intensive offloading I recommend you to look at solutions like EMC FAST Cache and Atlantis ILIO.
At the 101st minute mark the CBRC benefit is diminished due to the transition to the write intensive workload. However, if CBRC was enabled for persistent disks we would still have clear CBRC benefits.
Next, EMC ran an in-guest anti-virus scan storm. The graph below speaks for itself.
I would like to acknowledge the work from Jason Ventresco from EMC for running the validation tests and creating these fantastic comparative graphs. He also provided me with some awesome additional raw data that will allow me generate more information and articles over time.