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Community Member

IOS Upgrade failure - ELF Loader: read error

I just upgraded a Cisco 871 VPN router ios from c870-advipservicesk9-mz.124-24.T.bin TO the newer version >>c870-advipservicesk9-mz.124-24.T1.bin. Upon completion, I reloaded the router only to get the msg -

Booting flash:/c870-advipservicesk9-mz.124-24.T1.bin

ELF Loader: read error

Elf loader error

System Bootstrap, Version 12.3(8r)YI4, RELEASE SOFTWARE

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 2006 by cisco Systems, Inc.

C870 series (Board ID: 3-148) platform with 131072 Kbytes of main memory

Booting flash:/c870-advipservicesk9-mz.124-24.T1.bin

ELF Loader: read error

Elf loader error

And the router defaults to rommon mode.

I'd appreciate assistance getting it out of rommon and loading the older ios I removed. I will need to remove the new one I just loaded to make space on flash for the old one to be reloaded. I am at customer site right now, and need to bring this up ASAP. ouch.Thanks for any help.

12 REPLIES
Hall of Fame Super Gold

Re: IOS Upgrade failure - ELF Loader: read error

When in rommon, you can use tftpboot to load and boot with an IOS from a tftp seerver, like tftpd323.

Community Member

Re: IOS Upgrade failure - ELF Loader: read error

Paolo, thanks for the response, but I used tftpdnld, the file began loading but flash memory was insufficient to accomodate the old IOS. So I tried to delete the corrupted IOS on flash to create more space. when I tried this, I got a "permission denied" error msg. How can I force it to delete the corrupted IOS and? Pls see error msg

****

rommon 23 > delete c870-advipservicesk9-mz.124-24.T1

Are you sure you want to delete "c870-advipservicesk9-mz.124-24.T1" (y/n)?y

File "c870-advipservicesk9-mz.124-24.T1" not deleted -- permission denied

Cisco Employee

Re: IOS Upgrade failure - ELF Loader: read error

Hi,

Try using the full path description:

delete flash:c870-advipservicesk9-mz.124-24.T1

Also, if there is a "format" or "erase" command in the ROMMON mode, you may want to try that one to completely erase your entire FLASH. If its contents are corrupted, then this might be necessary.

Best regards,

Peter

Community Member

Re: IOS Upgrade failure - ELF Loader: read error

I tried deleting the Dir. instead of the file and got the same response.

rommon 26 > delete c870-advipservicesk9-mz.124-24.T1

Are you sure you want to delete "c870-advipservicesk9-mz.124-24.T1" (y/n)?y

File "c870-advipservicesk9-mz.124-24.T1" not deleted -- permission denied

rommon 27 >

There is a >rmdire command under rommon, but at this point I am not sure if I should even consider using it.

Cisco Employee

Re: IOS Upgrade failure - ELF Loader: read error

Hi,

You cannot delete a non-empty directory and you cannot delete the root directory.

Have tried using the format/erase command in the ROMMON?

Best regards,

Peter

Community Member

Re: IOS Upgrade failure - ELF Loader: read error

Erase is not an available option in rommon on the 871.

Fromat is available and rmdir is available, but I have no experience with their use in this mode, any help?

Cisco Employee

Re: IOS Upgrade failure - ELF Loader: read error

Hello,

The format command in the ROMMON performs a format operation on the FLASH. It effectively erases the entire FLASH including its contents.

The command is easy to use - simply write format flash:. After it finishes, you will need to download the proper IOS using the tftpdnld back to the FLASH.

Note that as every format operation, this command erases the entire FLASH with all files currently stored there.

Best regards,

Peter

Community Member

Re: IOS Upgrade failure - ELF Loader: read error

Thanks Peter, I was able to get TAC and worked with them to fix. But weird thing though, my config remained on the router and became the default when I tftpdnld'd the replacement IOS. I no longer see the config.text file, but that's okey, it works.

But my question, what could be the reason for the error below----

*****

Booting flash:/c870-advipservicesk9-mz.124-24.T1.bin

ELF Loader: read error

Elf loader error

*******

I cannot find any description/explanation for this IOS reload error. Thanks again

Hall of Fame Super Gold

Re: IOS Upgrade failure - ELF Loader: read error

Can be a corrupted image.

Cisco Employee

Re: IOS Upgrade failure - ELF Loader: read error

Hello,

I can only speculate here... The ELF is an acronym of the Executable and Linking Format and it describes a format of binary executable files. It is very popular in Unix-type operating systems and also it appears that the IOS images are basically compressed ELF binaries bundled with a decompression and startup routine.

The 'mz' images require that a decompression routine first decompresses the binary into RAM of the router and then proceeds to execute it. Apparently, the messages you see here are related to the fact that the decompression routine is not either able to find the image or it is having trouble decompressing and/or executing the unpacked IOS image.

I have noticed that on some Cisco platforms, the bootloader does not accept the first slash sign right after the colon. If the message still appears, try to enter the following command in the global configuration mode:

boot system flash c870-advipservicesk9-mz.124-24.T1.bin

and save the configuration. Then try to reload the router.

Best regards,

Peter

Community Member

Re: IOS Upgrade failure - ELF Loader: read error

Thank you all for your contributions. I was able to format flash: and tftpdnld the previous IOS.

Hall of Fame Super Gold

Re: IOS Upgrade failure - ELF Loader: read error

Very good, please remember to rate useful posts with the scrollbox below.

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