The online insertion and removal (OIR) feature supported on the Catalyst 6500 series switches allows you to remove and replace modules while the system is online. You can shut down the modules before the removal and restart it after insertion without the need for other software or interfaces to shut down.
When a module is removed or installed, the switch stops to process traffic for the module and scans the system for a configuration change. Each interface type is verified against the system configuration, and then the system runs diagnostics on the new module. There is no disruption to normal operation during module insertion or removal.
Note: Do not remove or install more than one module at a time. The switch can bring only an identical replacement module online. If the replacement module is different from the removed module, you must configure it before the switch can bring it online.