Rollback checkpoint files and rescue files are created with the rollback save command. A rollback checkpoint file can be saved at any time or configured to be automatically saved on a recurring schedule using the 7705 SAR CRON feature. For more information, see CRON.
Rollback checkpoint and rescue files contain all current operationally active configurations, including configuration changes from CLI commands in the config context and SNMP sets. Rollback checkpoint files are intended to be saved whenever there have been a moderate number of changes to the configuration, in order to create a series of intermediate checkpoints that operators can return to. The rollback rescue file is intended to be a permanent stable configuration that can be reverted to if needed.
Rollback checkpoint and rescue files do not contain any BOF configuration information or any configuration or state changes performed under the debug branch of the CLI. Similarly, performing a CLI configuration rollback never impacts the BOF configuration or any command from the debug CLI branch.
When a rollback save command is executed, a rollback checkpoint or rescue file is saved in the configured location. The latest rollback checkpoint file is saved with the suffix *.rb. The suffixes of all previously saved rollback checkpoint files are automatically incremented by one (*.rb becomes *.rb.1, *.rb.1 becomes *.rb.2, and so on). The rescue file is saved with the suffix *.rc.
By default, there can be 10 rollback checkpoint files, the latest with suffix *.rb and nine older files with suffixes *.rb.1 through *.rb.9. If the maximum number of checkpoint files is reached and a new one is saved, the oldest checkpoint file is deleted. The maximum number of rollback checkpoint files that can be saved can be configured with the local-max-checkpoints and remote-max-checkpoints commands.
There can only be one rollback rescue file. When a new rescue file is saved, the existing file is deleted. The rescue file is not impacted by the number of rollback checkpoint files — there will always be one rescue file available.
Operators can view a list of rollback checkpoint or rescue files with the rollback view command. The following information is displayed for the files:
date and time stamps
file index and suffix
the user who created the file
release number
comment string
A rollback compare command is also available that allows operators to compare different checkpoint files to each other or to the current operating configuration. The command output highlights any differences between the configurations.
Rollback checkpoint and rescue files are not editable or interchangeable with configuration files, such as those generated with an admin save command.
Both admin save and rollback save should be performed periodically. The admin save command backs up the complete configuration file to be used during a router reboot and should be performed after any major service changes or hardware and software upgrades. The rollback save command should be performed to create intermediate checkpoints whenever a moderate number of changes have been made to the configuration.
Rollback checkpoint files and rescue files can be deleted with the dedicated admin>rollback>delete command. When a checkpoint file is deleted, the suffix ID numbers of all older files are automatically decremented.
If a rollback checkpoint file is manually deleted, using, for example, the file delete command, the suffix ID numbers of older checkpoint files are not decremented, nor is the backup checkpoint file deleted from the standby CSM. This creates a gap in the checkpoint file list. New rollback checkpoint files can still be created, but the gap is not filled until enough files have been created to roll the gap off the end of the list.