A virtual storage server (Vserver) contains data volumes and one or more LIFs through which it serves data to the clients. Starting with clustered Data ONTAP 8.1.1, a Vserver can either contain one or more FlexVol volumes, or a single Infinite Volume.
A Vserver securely isolates the shared virtualized data storage and network, and appears as a single dedicated server to its clients. Each Vserver has a separate administrator authentication domain and can be managed independently by a Vserver administrator.
In a cluster, Vserver facilitates data access. A cluster must have at least one Vserver to serve data. Vservers use the storage and network resources of the cluster. However, the volumes and LIFs are exclusive to the Vserver. Multiple Vservers can coexist in a single cluster without being bound to any node in a cluster. However, they are bound to the physical cluster on which they exist.
A cluster can have one or more Vservers with FlexVol volumes and Vservers with Infinite Volumes.
A Vserver with FlexVol volumes in a NAS environment presents a single directory hierarchical view and has a unique namespace. Namespace enables the NAS clients to access data without specifying the physical location of the data. Namespace also enables the cluster and Vserver administrators to manage distributed data storage as a single directory with multiple levels of hierarchy.
The volumes within each NAS Vserver are related to each other through junctions and are mounted on junction paths. These junctions present the file system in each volume. The root volume of a Vserver is a FlexVol volume that resides at the top level of the namespace hierarchy; additional volumes are mounted to the Vserver's root volume to extend the namespace. As volumes are created for the Vserver, the root volume of a Vserver contains junction paths.
A Vserver with FlexVol volumes can contain files and LUNs. It provides file-level data access by using NFS and CIFS protocols for the NAS clients, and block-level data access by using iSCSI, and Fibre Channel (FC) protocol (FCoE included) for SAN hosts.
A Vserver with Infinite Volume can contain only one Infinite Volume to serve data. A Vserver with Infinite Volume includes only one junction path, which has a default value of /NS. The junction provides a single mount point for the large namespace provided by the Vserver with Infinite Volume. You cannot add more junctions to a Vserver with Infinite Volume. However, you can increase the size of the Infinite Volume.
A Vserver with Infinite Volume can contain only files. It provides file-level data access by using NFS and CIFS (SMB 1.0) protocols. A Vserver with Infinite Volume cannot contain LUNs and does not provide block-level data access.