> # Automatic Failover and Fallback

> As of Cisco MDS NX-OS Release 4.1(1a), SAN device virtualization supports automatic failover and fallback configurations for the virtual devices. In all of the earlier releases, when there was a failure, you needed to manually configure the device as primary to make it active. With the introduction of automatic failover and fallback configurations, the active device is distinguished from the primary device indicated by a (*) symbol.

> - Auto failover—When there is a failure, the failover auto attribute automatically shuts down the primary device and brings up the secondary device to active state. When the primary device comes back online, it requires user intervention to switchover.
> - Auto failover with fallback—In addition to automatic failover, when the primary device comes back online after a failover, the primary device is brought to active state and the secondary device moved to standby state.

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