Virtual SAN and Traditional Storage

Although Virtual SAN shares many characteristics with traditional storage arrays, the overall behavior and function of Virtual SAN is different. For example, Virtual SAN can manage and work only with ESXi hosts and a single Virtual SAN instance can support only one cluster.

Virtual SAN and traditional storage also differ in the following key ways:

• Virtual SAN does not require external networked storage for storing virtual machine files remotely, such as on a Fibre Channel (FC) or Storage Area Network (SAN).
• Using traditional storage, the storage administrator preallocates storage space on different storage systems. Virtual SAN automatically turns the local physical storage resources of the ESXi hosts into a single pool of storage. These pools can be divided and assigned to virtual machines and applications according to their quality of service requirements.
• Virtual SAN has no concept of traditional storage volumes based on LUNs or NFS shares, although the iSCSI target service uses LUNs to enable an initiator on a remote host to transport block-level data to a storage device in the Virtual SAN cluster.
• Some standard storage protocols, such as FCP, do not apply to Virtual SAN.
• Virtual SAN is highly integrated with vSphere. You do not need dedicated plug-ins or a storage console for Virtual SAN, compared to traditional storage. You can deploy, manage, and monitor Virtual SAN by using the vSphere Web Client.
• A dedicated storage administrator does not need to manage Virtual SAN. Instead a vSphere administrator can manage a Virtual SAN environment.
• With Virtual SAN usage, VM storage policies are automatically assigned when you deploy new VMs. The storage policies can be changed dynamically as needed.