State Database and State Database Replicas

The state database is a database that stores information on disk about the state of your Solaris Volume Manager configuration. The state database records and tracks changes made to your configuration. Solaris Volume Manager automatically updates the state database when a configuration or state change occurs. Creating a new volume is an example of a configuration change. A submirror failure is an example of a state change.

The state database is actually a collection of multiple, replicated database copies. Each copy, referred to as a state database replica, ensures that the data in the database is always valid. Having copies of the state database protects against data loss from single points-of-failure. The state database tracks the location and status of all known state database replicas.

Solaris Volume Manager cannot operate until you have created the state database and its state database replicas. It is necessary that a Solaris Volume Manager configuration have an operating state database.

When you set up your configuration, you can locate the state database replicas on either of the following:

• On dedicated slices

• On slices that will later become part of volumes

Solaris Volume Manager recognizes when a slice contains a state database replica, and automatically skips over the portion of the slice reserved for the replica if the slice is used in a volume. The part of a slice reserved for the state database replica should not be used for any other purpose.

You can keep more than one copy of a state database on one slice. However, you might make the system more vulnerable to a single point-of-failure by doing so.

The system will continue to function correctly if all state database replicas are deleted. However, the system will lose all Solaris Volume Manager configuration data if a reboot occurs with no existing state database replicas on disk.