StarWind Resource Library

StarWind Virtual SAN Free Overview

Fill in the Form to Continue

Published: March 22, 2016

Value Proposition

For virtualization admins, IT geeks, bloggers, students or those who look to build and maintain virtualization infrastructure for test and development, home lab or POC (Proof of Concept) at little to no expense, our solution is StarWind Virtual SAN Free. It is software that creates “shared nothing” faulttolerant SAN or NAS for personal or production use from just two commodity servers. It also does 2- node hyperconverged infrastructure as an option, restricted to certain use cases.

StarWind Virtual SAN Free targets those who need a SAN or NAS for their home lab, educational or research purposes. It is free for production use, but comes with a basic restricted set of features, compared to the full VSAN. In case a serious project is starting, StarWind Virtual SAN will come in handy. It offers a wider set of features unlocked and more usage scenarios, also being backed by StarWind support. Getting qualified assistance from expert engineers simplifies the building and maintenance of virtualization infrastructure. The complete list of differences between free and paid versions can be found here. In case there is no time for “Do-It-Yourself” tinkering, StarWind offers a turnkey solution – StarWind HyperConverged Appliance. It unifies best-of-breed software and hardware from multiple vendors and covers it with one “support umbrella”.

StarWind turns a pair of commodity servers into fault-tolerant SAN and NAS


Unlike open-source free software of similar purpose, our solution is based on in-house developed code, proven to work by years of successful StarWind VSAN usage. It is a native Windows application, without any custom Linux/FreeBSD fork-outs and hours of tinkering. Though self-supported, StarWind Virtual SAN Free was designed to simplify installation, maintenance and possible troubleshooting.

Unlike free versions of typical Software Defined Storage solutions, ours is a production platform. StarWind Virtual SAN Free is more than just a “marketing vehicle” – trial or demonstration software for selling the paid version. It has commercial grade functionality and real-life use cases, such as: virtual shared storage for Microsoft Hyper-V and SQL Server, virtual shared storage for VMware vSphere & ESXi and Xen, failover file server, backup storage (corporate data, VDI profiles), etc.
Full differentiation of StarWind Virtual SAN against competitors can be found here.




The free VSAN can also create a hyperconverged infrastructure, though the option is restricted to certain user statuses. This architecture unifies compute and storage resources on the same layer, thus being easily managed on the hypervisor level. It also requires less hardware to purchase, meaning both servers and associated network infrastructure. Hyperconverged architecture also boosts performance, because StarWind takes care of “data locality”, trying to keep storage on the same node with VMs. This way most of I/O becomes local, without going through wire and performance grows.

StarWind Virtual SAN hyperconverged architecture

Converged (Compute and Storage Separated)

StarWind Virtual SAN Free manages segregated storage layer working in pair with compute resources. This architecture is great for infrastructures where there is a need to grow capacity or performance independently from each other, such as big clustered SQL Server and Oracle deployments. Such a scenario can fit the task easier by adding either CPU/RAM to the hypervisor node or disks to storage node. Being flexible, it gives more freedom in terms of scaling.

StarWind Virtual SAN compute and storage separated architecture

Unified Storage (Multiprotocol)

StarWind Virtual SAN Free is a full-fledged production platform that supports multiple uplink protocols and provides various usage scenarios. They include: Shared storage for Microsoft Hyper-V VMs and SQL Server DBs (CA SMB3), Shared storage for VMware vSphere & ESXi, Citrix XenServer and various Xen VMs (NFS), Failover file server (SMB3 & NFS). There is also a special version that supports VMware Virtual Volumes functionality.

VM-Centric Storage and StarWind Log-Structured File System (LSFS)

StarWind Virtual SAN Free was specifically designed to handle VM workload. It successfully fights random I/O, which is typical for virtualization, utilizing Log-Structured File System and smart caching. This way, “I/O Blender” effect is negated and performance is kept high without uberexpensive all-flash model.

Server-Side Cache

StarWind Virtual SAN Free implements distributed RAM and flash caches to reduce network traffic to the absolute minimum and reduce I/O latency. The caches are also “mirrored” between the nodes, being not only fast, but also safe. Using commodity hardware for caching and employing “data locality”, StarWind Virtual SAN Free raises performance without breaking the bank.

Fault Tolerance and High Availability

Storage and caches are “mirrored” between multiple nodes, achieving 99.99% uptime with 2-way replica and 99.9999% with 3-way replica. Every active host acts as a storage controller and every Logical Unit has its data replicated on multiple nodes. It would take an improbably extensive failure to cause downtime, because the system is impervious to entire storage hosts crashing.

Scale-Up and Scale-Out

The hyperconverged version of StarWind Virtual SAN Free supports the full scaling capabilities of StarWind Virtual SAN. Disks, flash, RAM and CPUs can be added to scale up and ready-nodes can be added to scale-out. The converged version was not designed for scaling, so StarWind VSAN should be considered instead.

Hardware Agnostic and Commodity Hardware

StarWind Virtual SAN Free will run on inexpensive commercial off-the-shelf hardware, without any mandatory proprietary components or “magic hardware”. Two general-purpose servers are everything the user needs to create a fault-tolerant SAN or NAS, nothing else is mandatory, including network switches. All the “top of the line” components are not required, but StarWind Virtual SAN Free still supports them, including high-performance SAS, durable SLC flash and 10- 100 GbE network.

Asynchronous Replication

StarWind Virtual SAN Free is the only free solution of the type to support asynchronous replication to public cloud. Using Azure with geo-redundancy as a Disaster Recovery site for mission-critical data eliminates any need in a remote location and forms a backup solution at little to no effort. Basically, it is an entire backup infrastructure without additional hardware.

Snapshots and Automated Storage Tiering

StarWind Virtual SAN Free may be configured to use Azure as DR site, offloading snapshots to the cloud. Enabling geo-clustering creates a full-fledged backup solution without any hardware investments using only StarWind Virtual SAN Free and Azure public cloud.

Deduplication and Compression

StarWind Virtual SAN Free inherits Virtual SAN space reduction technologies: deduplication and compression for storage and caches. StarWind brings to table its own 4K in-line dedupe and leverages Microsoft’s offline dedupe, allowing to combine them as the user sees fit. The technology conserves capacity, accelerating performance with “virtually bigger” cache, and prolonging flash life, because the amount of writes goes down. The outcome is calculated in terms of cost: higher performance and capacity on the same hardware.

Virtual Storage Appliance

StarWind Virtual SAN trial version is available for fast deployment from a pre-configured VMware and Hyper-V compatible VM. It may not give a clear view on performance, residing in a Virtual Machine, but it shows all the features available in StarWind Virtual SAN.

Virtual Tape Library (VTL)

StarWind Virtual SAN Free does not include the VTL plugin for obvious reasons. Its typical use cases do not involve tape backup solutions. However, if for any reason, it is necessary to deal with tape hardware, StarWind VSAN may come in handy with its VTL plugin. It accelerates backup and fits the process into backup window, avoiding overlap with production time and performance degradation.