Flash - Read only file system

[sannymlao]

Good day,

I have a switch cisco ws-3650 -24ps-s which in rommon mode "switch:" I tried to boot packages.cnf but keeps rebooting.

I tried to copy a new IOS version in rommon mode  to flash: but I got a message which indicates an error  "Read only file system."

Could you please help me on how to copy IOS in rommon mode to flash successfully?

Your help is very much appreciated.

Thank you and regards,

Sanny

[Milosz Jablonski]

Hi guys

I read the below replies etc and see a bit of an issue.

This is common that when you buy a 2nd hand device on ebay or elsewhere it may come with all its config. So, the original question to this was - how to manage files "under the hood OF the IOS". The workaround it can be found here:
https://community.spiceworks.com/topic/875130-unlocking-pre-boot-flash-memory-on-cisco-3850-poe

on the newer boxes ie. 3650 switches the command to issue in ROMON is SWITCH_IGNORE_STARTUP_CFG=1

It worked for me but check your model command reference

You're in ROMON to install IOS (hope you have one), The best way nowadays is to  set your switch to use TFTP or install it from USB - is is really quick.

Those pointing to emergency-install from USB or TFTP are right in a way that Cisco by default thinks of using ROMON only if something drastic happens. The idea of ROMON is to be basically able to perform IOS installation and/other emergency kind of works and then to get to flash once the system is up  and running. Unless you want to keep it in ROMON for some reason :)
Suggestion - guys, this is a techies forum where I would love to see to the point answers not throwing junk at each other...

Anayway, hope this helps to do whatever you wanted...

thanks

[jason.hsu]

Same problem but on a 9300. I had formatted flash due to update failing with a disk space error; btw I had tried all the clean commands to delete anything old prior. I will never do this again; now it won't recognize USB stick (fat32) and no option to copy file to flash. I did try the tftp boot and that just freezes while copying the file; tftp server log says client disconnected. This is the worst Cisco switch I have ever tried to update. I think we'll be RMA'ing this one and if there is disk space error on an update I simply will ignore it and not update, this has been nothing short of a disaster.

[Leo Laohoo]

Just RMA the unit.  

All members of our team have a USB stick they carry for cases like this.  

[superation237]

So my issue was the switch was completely wiped. When I say completely I mean 

flash:packages.conf

 didn't even exist. Because of this trying to do emergency-install or anything else didn't work. What did work was the "set" command. I changed the BOOT to the usbflash0:my.bin and it loaded when I issued the reset command. I had to get the older version of the IOS. Gibraltar didn't work so i had to use the cat3k_caa-universalk9.SPA.03.06.10.E.152-2.E10.bin. So if everything else is failing but you can read the USB change the boot with the "set" command.

Recap of commands I used:

set BOOT usbflash0:cat3k_caa-universalk9.SPA.03.06.10.E.152-2.E10.bin

reset

this launched the bin.  "Front-end Microcode IMG MGR: HW image is upgraded" was the end result with it booting into IOS.