1-8Coexistence of multiple configuration filesMultiple configuration files can be stored on a storage medium of a device. You can save theconfiguration used in different environments as different configuration files. In this case, when thedevice moves between these networking environments, you just need to specify the correspondingconfiguration file as the startup configuration file for the next boot of the device and restart the device,so that the device can adapt to the network rapidly, saving the configuration workload.A device boots using only one configuration file. However, you can specify two startup configuration files,main and backup startup configuration file, for the next startup of the device as needed. When thedevice boots, the system uses the main startup configuration file, and if the main startup configurationfile is corrupted or lost, the system will use the backup startup configuration file for device boot andconfiguration. The devices supporting the configuration of the main and backup startup configurationfiles, compared with the devices that do not support this feature, are more secure and reliable.At a moment, there are at most one main startup configuration file and one backup startup configurationfile. You can specify neither of the two files (displayed as NULL), or specify the two files as the sameconfiguration file.You can specify the main and backup startup configuration files for the next boot of the device in thefollowing two methods:z Specify them when saving the current configuration. For detailed configuration, refer to Saving theCurrent Configuration.z Specify them when specifying the startup configuration file for the next system startup. For detailedconfiguration, refer to Specifying a Startup Configuration File for the Next System Startup.Startup with the configuration fileThe device takes the following steps when it boots:1) If the main startup configuration file exists, the device initializes with this configuration file.2) If the main startup configuration file does not exist but the backup startup configuration file exists,the device initializes with the backup startup configuration file.3) If neither the main nor the backup startup configuration file exists, the device will boot with nullconfiguration (boot with null configuration means to boot with the factory default configuration).Saving the Current ConfigurationIntroductionYou can modify the current configuration on your device using command line interface. However, thecurrent configuration is temporary. To make the modified configuration take effect at the next boot of thedevice, you must save the current configuration to the startup configuration file before the devicereboots.Modes in saving the configurationz Fast saving mode. This is the mode when you use the save command without the safely keyword.The mode saves the file more quickly but is likely to lose the existing configuration file if the devicereboots or the power fails during the process.z Safe mode. This is the mode when you use the save command with the safely keyword. The modesaves the file more slowly but can retain the configuration file in the device even if the devicereboots or the power fails during the process.
