Cisco 3600 Flash Memory Upgrade

Unanswered Question
Nov 16th, 2007

Hi All,

We just upgraded a 3640 Router Flash Memory from 8+8 MB to 16+16 MB. After the Upgrade we are trying to upload a Latest IOS(which is 21 MB) and we get the following error.


rommon 7 > xmodem -c c3640-jk9o3s-mz.123-24.bin

Do not start the sending program yet...

device does not contain a valid magic number

dir: cannot open device "flash:"

WARNING: All existing data in flash will be lost!

Invoke this application only for disaster recovery.

Do you wish to continue? y/n [n]: y

get_man_dev: Unknown device - probably NOT formatted.

get_man_dev: Unknown device - probably NOT formatted.

Ready to receive file c3640-jk9o3s-mz.123-24.bin ...


ERR:Image size exceeds free flash space


Someone throw some light on how to get this resolved.

Thanks in Advance,

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desai.jaideep Fri, 11/16/2007 - 03:16


You need to format flash first.

The better way out is to use "-r" switch.

This will boot the router using IOS loaded in RAM. Then ypu can format and upload the IOS. This would be fast in compared to xmodem.

Pls do comeback if u face problem.



subra4u Fri, 11/16/2007 - 04:02


Thanks for the immediate response. I tried but with no luck. Please find the details below.


rommon 8 > boot -r

NOTE: Boot options -r, -n, and -a are for debugging with GDB.

device does not contain a valid magic number

boot: cannot open "flash:"

boot: cannot determine first file name on device "flash:"


Thanks in Advance


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