Core Issue
If a Cisco IOS Software upgrade is performed by issuing the xmodem command from ROM Monitor (ROMmon) mode, and the router boots successfully but no image is in the Flash, then the [-r] option was used when the xmodem command was issued.
The [-r] option causes the Cisco IOS image to be written only to RAM but not to the Flash. This option can be useful if a Flash issue exists or if time is critical in getting the router up and running. The process is shorter since the Flash write does not occur. However, because the Cisco IOS Software is only in RAM, a power failure or reload will send the router back to ROMmon mode since no image is in the Flash. If that happens, the router may report the following error message on the console before falling to ROMmon:
device does not contain a valid magic number
Resolution
If the xmodem -r command was issued to load the Cisco IOS Software, perform the following steps to copy an image to the Flash:
- Do not reload or power off the router.
- If possible, copy the Cisco IOS Software image to the Flash using TFTP as shown in the Software Upgrade Procedure.
- If the TFTP option is not available, issue the xmodem command again without the [-r] option.
For details about the xmodem command and options, refer to Xmodem Console Download Procedure Using ROMmon.
