Hi Leo,

The "eusb" is a type of flash disk that is used the ISR 4331 routers.  We are upgrading the memory, but when the memory is updated larger than the current Flash Memory, the system indicates you must upgrade the Flash as well.  

On the ISR 4331 there is 4GB of Flash on board, to upgrade you need to use eusb. So since we have upgraded the memory to 16GB, we are trying to upgrade the Flash as well.

If we install the eusb while the router is powered off, when the router tries to boot, it thinks the IOS is on the eusb, and cause a bootloop because there is no valid IOS on the eusb. 

If I boot the router first, and then install the eusb while the router is running, the router sees and displays the eusb being installed, the issue now is that it does not show in any of the directories.  

I then thought it must have to be formatted, when the format command is given the only option is bootflash.  I can't format the bootflash because it will delete the IOS.

So that is where I am at now, any ideas?

Thank you

Chris

Ok, now I understand what this is.  

The eUSB is the flash.  So when you upgrade from the default 4 Gb flash/eUSB to something bigger, then the new one will have NOTHING in it.  

It is recommended to copy the IOS and the startup-config from the appliance to an external USB stick.  Once the new eUSB is installed you can boot the IOS from the external USB stick from ROMmon.  Once the appliance boots up then you can copy the IOS and the startup-config from the external USB stick to the newly upgraded flash/eUSB. 

The problem with this is there is no hardware installation guide which will direct anyone WHAT the eUSB looks like and WHERE the eUSB is located inside.  The only way is to contact Cisco TAC and get them to send out the guide(s) to you.

This one worked for me when upgrading from 4 Gig flash to 16 Gig flash..

https://www.cisco.com/c/en/us/td/docs/routers/access/4400/flashmemory/isr4000_flashmem.html

BR

Espen.