Junos OS supports only 1 rescue configuration file on a device. This rescue configuration is a safeguard feature that allows network administrators to revert to a known good configuration in case of a configuration error or issue, ensuring network stability.
In Junos OS, each device supports only one rescue configuration file. The rescue configuration is a specific configuration that can be saved and later retrieved if needed. This is used as a fallback configuration that you know works and can be applied in case of an emergency or if the current configuration has issues.
Reference:
"You can create a rescue configuration file by using the request system configuration rescue save operational mode command. Each Junos OS device can have only one rescue configuration file."