Backing Up the Committed Configuration on the Alternate Boot Drive
After you commit the configuration and are satisfied that it is running successfully, you should issue the request system snapshot command to back up the new software onto the /altconfig file system. If you do not issue the request system snapshot command, the configuration on the alternate boot drive will be out of sync with the configuration on the primary boot drive.
The request system snapshot command backs up the root file system to /altroot, and /config to /altconfig. The root and /config file systems are on the router’s flash drive, and the /altroot and /altconfig file systems are on the router’s hard disk (if available).
 | Note: To back up the file system on a J Series Services Router, you must specify a media type (primary compact flash drive, removable compact flash drive, or USB storage device) for backup. For more information about the request system snapshot command, see the Junos OS Operational Mode Commands. |
| Note: For more information about backing up the file system on an ACX Series Universal Access Router, see Understanding System Snapshot on an ACX Series Router. |
After you issue the request system snapshot command, you cannot return to the previous version of the software because the running and backup copies of the software are identical.
