VMware vSphere® Storage Appliance (VSA) is a VMware virtual appliance that packages SUSE Linux Enterprise Server 11 and storage clustering services. A
VSA virtual machine runs on several ESXi hosts to abstract the storage resources that are installed on the hosts and to create a vSphere Storage Appliance cluster (VSA cluster).
What Is a VSA Cluster? A VSA cluster leverages the computing and storage resources of several ESXi hosts and provides a set of datastores that are accessible by all hosts within the datacenter.
VSA Cluster Components vSphere components together with the required hardware setup and configuration form a VSA cluster.
VSA Cluster Architecture The architecture of a VSA cluster includes the physical servers that have local hard disks, ESXi as the operating system of the physical servers, and the vSphere Storage Appliance virtual machines that run clustering services to create volumes that are exported as the VSA datastores via NFS.
VSA Cluster Network Architecture The physical network of a VSA cluster consists of Ethernet switches and network interface cards (NICs) that are installed on each host.
How a VSA Cluster Handles Failures A VSA cluster provides automatic failover from hardware and software failures.
Differences Between VSA Clusters and Storage Area Networks A VSA cluster is a virtual alternative to expensive SAN systems. While SAN systems provide centralized arrays of storage over a high-speed network, a VSA cluster provides a distributed array that runs across several physical servers and utilizes local storage that is attached to each ESXi host.
VSA Cluster Capacity The total capacity of a VSA cluster is the sum of the capacities of all VSA datastores. Depending on the RAID configuration of your VSA cluster, you use different algorithms to calculate VSA capacity.
Licensing vSphere Storage Appliance vSphere Storage Appliance requires a license key to operate. You can use the vSphere licensing infrastructure for VSA license management.