Virtunet Systems
4117 Park Blvd
Palo Alto, CA , USA

+1 (650) 847 8633

Solution Offering

VirtuCache is a software solution that caches frequently used blocks of data from traditional disk-based shared storage to in-server solid state storage, thus eliminating storage I/O bottlenecks for data-intensive workloads deployed within VMs.


  • Significantly improves storage IOPS and throughput
  • Results in lower hardware cost-per-IOPS and MB/s versus upgrading SAN infrastructure
  • Increases VM density by fully utilizing CPU, memory and networking resources


  • Support for read-only (write around) and write-through caching
  • Only a single software component needs to be installed within the hypervisor. No agents required in guest VMs. No storage reconfiguration required.
  • Ability to control caching policy at VM, disk, volume, server, logical unit number (LUN)
  • Full support for virtualization features, such as live VM migration, high availability and live storage migration
  • Older, infrequently used blocks are replaced with newer, more recently used ones using Least Recently Used (LRU) and first-in, first-out (FIFO) algorithms.
  • Data center-wide cache management using a CLI or GUI within virtualization management console (VMware vCenter)
  • No data loss in case of power outage

High Performance
VirtuCache is the highest-performance caching software for Virtualization Software because:

  • All software components in the I/O path are in the hypervisor kernel. No VM or Userspace software.
  • Identical requests made by multiple VMs are cached only once.
  • Automatically identifies large sequential reads and prevents such reads from replacing existing cache data
  • Cache metadata is stored in RAM to quickly decide if the block has to be fetched from cache or shared storage.

Minimal Administration
VirtuCache is a fully automated caching software and requires zero administration.

  • Dynamically caches blocks from FC, iSCSI, FCoE, Direct Attached Storage to in-server solid state storage.
  • Dynamically allocates cache across VMs. Administrator only needs to specify cache capacity for each server.

Value Proposition

Cloud deployments rely on virtualization platforms, like VMware, to deploy applications within VMs. By deploying VirtuCache in the VMware kernel, storage throughput is improved and storage latencies are reduced considerably, resulting in predictable and consistent application performance. It also allows VMware administrators to deploy a larger number of VMs on each server, thus reducing hardware costs, power consumption and VMware licensing costs.

An alternate approach to improving storage throughput is to deploy all-flash arrays and/or deploying higher-throughput SAN switches and HBAs.

The following are competitive differentiators of VirtuCache versus SAN upgrades and all-flash arrays:

  1. Non-disruptive: Unlike a SAN upgrade that results in customers throwing away older equipment, Virtunet improves the performance of the customer’s existing SAN.
  2. Incremental deployment versus a larger upfront investment with a SAN upgrade: Our software can be deployed incrementally as and when there are storage I/O issues on servers.
  3. Plug and play: Customers can install our driver software in under 5 minutes, plug in an SSD into a server, and see performance improvements right away.
  4. Better performance than all-flash arrays: Our software with commodity SSDs provides up to 50,000 IOPS to each server, which, on a per-server basis, is better performance than an all-flash storage appliance.

Some advantages of using VirtuCache over other server-side caching software, such as Fusion-io ioTurbine, EMC XtremeSW and NetApp Flash Accel, are:

  1. We have 2× the throughput on the same hardware, primarily because our software runs in the VMware kernel, whereas theirs requires software installed in the guest VMs.
  2. Because we do not require any software installed in the guest VMs, we support any OS in VMs. They support only a few server OSs in VMs, making their software unusable in VDI deployments that implement consumer OSs, and in IAAS deployments where the service provider does not have access to the customer’s VMs.
  3. We are completely automated. Software from these other vendors must be manually configured in each guest VM to be effective.

Why Seagate

Because Seagate offers solid state drives (SSD) in all interface types–SAS, SATA and PCIe, we are able to offer VirtuCache deployed along with any of these SSDs at various price-performance levels depending on customer requirements for throughput, slot availability on the motherboard, capacity and latencies.

The Seagate® X8 Accelerator (powered by Virident) is one of the best-performing PCIe cards on the market and is less expensive than similar PCIe cards from Fusion-io and LSI.

Company Description

Virtunet Systems is developing products for addressing storage needs in VMware, Hyper-V as well as Linux-based hypervisors.

Our first product, VirtuCache, is a software solution that caches frequently used blocks of data from traditional disk- based shared storage to in-server solid state storage, thus eliminating storage I/O bottlenecks for data-intensive workloads deployed within virtual machines (VM).