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Replaced PernixData for vGPU based VDI

First of all – PernixData was a good host side caching software. Unfortunately for their customers, after they were acquired by Nutanix, Nutanix end-of-lifed their software. Our software, called VirtuCache, directly competes with PernixData FVP.

vGPU is new functionality in VMware vSphere 6.0 where a physical GPU installed in an ESXi host can be shared across multiple VMs.

These GPU reliant applications are storage IO intensive, since GPUs are used in situations where large computations need to rapidly happen on large volumes of data. So it helps if the data that the GPUs are working on is cached locally to in-VMware host high speed media instead of being retrieved from backend storage all the time. This is what VirtuCache does.

Western Digital moved from PernixData for ESXi 6.0 to VirtuCache for ESXi 6.5

WD is one of the largest manufacturers of Hard Drives. Their manufacturing unit was using VMware View 6.0 virtual desktops with vGPUs for their CAD/CAM applications, and Fiber Channel Hitachi storage. They were successfully using PernixData’s FVP software which was caching from HDS datastores to in-VMware host Intel P3700 NVME SSDs.

They wanted to move to ESXi 6.5 to benefit from the new vGPU High Availability functionality in ESXi 6.5. Since PernixData had recently end-of-lifed (2017) their host side caching software and also because PernixData FVP did not support ESXi 6.5, WD decided to move to VirtuCache for this same functionality.

The reasons WD went with VirtuCache versus others in this space:

  1. VirtuCache accelerates writes in addition to reads. Most other host side caching vendors only accelerate reads. CAD workload involves reading large amounts of data, doing rapid computations on it and writing newly derived data which is more voluminous than the original data. Since the workload was write intensive, it was important to accelerate writes.
  2. WD wanted to speedup both the VM spin-up process and performance of applications within VMs. The storage IO for VM creation originates in the VMware kernel. Storage IO for applications running within VMs originates in the VMs. Only VirtuCache accelerates both VMware kernel generated IO and application IO from within VMs, since VirtuCache is the only kernel mode VMware host side caching software, and so it has visibility to both kernel and VM IO.
  3. VirtuCache matched storage throughput and latencies of PernixData FVP almost exactly for random small block reads and writes, which was their most pressing problem.