Systems

A system is a collection of SAN Volume Controller nodes.

A system can consist of between two to eight SAN Volume Controller nodes.

All configuration settings are replicated across all nodes in the system. Management IP addresses are assigned to the system. Each interface accesses the system remotely through the Ethernet system-management addresses, also known as the primary, and secondary system IP addresses.

System management
A clustered system is managed by using a command-line session or the management GUI over an Ethernet connection.
Management IP failover
If the configuration node fails, the IP addresses for the clustered system are transferred to a new node. The system services are used to manage the transfer of the management IP addresses from the failed configuration node to the new configuration node.
System state
The state of the clustered system holds all of the configuration and internal data. The system state information is held in volatile memory.
Configuration backup and restore process
Configuration backup is the process of extracting configuration settings from a clustered system and writing it to disk. The configuration restore process uses backup configuration data files for the system to restore a specific system configuration. Restoring the system configuration is an important part of a complete backup and disaster recovery solution.
System high availability
A SAN Volume Controller clustered system has several features that can be used to deploy a high-availability storage system with no single point of failure.
System configuration by using SAN fabrics with long-distance fiber connections
Each clustered system that uses SAN fabric switches can use shortwave or longwave optical fiber connections connect to application hosts, storage systems, or remote systems.
Stretched systems
A stretched system is an extended high availability (HA) method that is supported by SAN Volume Controller to enable I/O operations to continue after the loss of half of the system. A stretched system is also sometimes referred to as a split system because one half of the system and I/O group is usually in a geographically distant location from the other, often 10 kilometers or more. A third site is required to host a storage system that provides a quorum disk.

Parent topic: Technical overview