Information About High Availability
The purpose of high availability (HA) is to limit the impact of failures—both hardware and software— within a system. The Cisco NX-OS operating system is designed for high availability at the network, system, and service levels.
The following Cisco NX-OS features minimize or prevent traffic disruption in the event of a failure:
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Redundancy—Redundancy at every aspect of the software architecture.
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Isolation of processes—Isolation between software components to prevent a failure within one process disrupting other processes.
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Restartability—Most system functions and services are isolated so that they can be restarted independently after a failure while other services continue to run. In addition, most system services can perform stateful restarts, which allow the service to resume operations transparently to other services.
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Supervisor stateful switchover—Active/standby dual supervisor configuration. The state and configuration remain constantly synchronized between two Virtual Supervisor Modules (VSMs) to provide a seamless and stateful switchover in the event of a VSM failure.
Starting with Release 4.2(1)SV2(1.1), the high availability functionality is enhanced to support the split active and standby Cisco Nexus 1000V Virtual Supervisor Modules (VSMs) across two data centers to implement the cross-DC clusters and the VM mobility while ensuring high availability.