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Help, FLASH is read-only

Hi,

I am trying to upgrade the IOS on a AS2511, flash is listed as read only.

System flash directory:

File Length Name/status

1 8030024 c2500-ins-l.120-22.bin

[8030088 bytes used, 8747128 available, 16777216 total]

16384K bytes of processor board System flash (Read ONLY)

I do not see an option to chang the flash from read only, to read write.

How can this be changed so I can change the contents of flash, upgrade the IOS?

Thanks in advance for your help.

Ziggy Pijewski

1 ACCEPTED SOLUTION

Accepted Solutions

Re: Help, FLASH is read-only

There are two types of routers - run from flash or run from ram.

2500, 1600 routers are Run from flash routers. The IOS is not fully decompressed into the ram, some are left in the flash, and hence flash should not be erased under normal operation. Hence your flash is showing read only in normal router mode.

To make it read write, do the following.

Router (config)#config-register 0x2101

The above setting changes the config register to 2101 which boots the router into Rxboot mode. Rxboot mode is a router mode with no routing capability. This mode is used for maintenance of router, like upgrading IOS etc.

After settiing the router register as 0x2101, reboot the router. The router will boot into Rxboot mode ( indicated by Router(boot)#)

In this mode you can copy any file to flash, as the flash will be read write mode.(To copy file, you need to use "copy tftp flash" in the Rxboot mode)

Once you finish copying the file to flash, change the config register back to 0x2102.

Router(boot)#config terminal

Router(boot)(config)#config-register 0x2102.

reload the router and you should be back with your new IOS booted.

2 REPLIES

Re: Help, FLASH is read-only

There are two types of routers - run from flash or run from ram.

2500, 1600 routers are Run from flash routers. The IOS is not fully decompressed into the ram, some are left in the flash, and hence flash should not be erased under normal operation. Hence your flash is showing read only in normal router mode.

To make it read write, do the following.

Router (config)#config-register 0x2101

The above setting changes the config register to 2101 which boots the router into Rxboot mode. Rxboot mode is a router mode with no routing capability. This mode is used for maintenance of router, like upgrading IOS etc.

After settiing the router register as 0x2101, reboot the router. The router will boot into Rxboot mode ( indicated by Router(boot)#)

In this mode you can copy any file to flash, as the flash will be read write mode.(To copy file, you need to use "copy tftp flash" in the Rxboot mode)

Once you finish copying the file to flash, change the config register back to 0x2102.

Router(boot)#config terminal

Router(boot)(config)#config-register 0x2102.

reload the router and you should be back with your new IOS booted.

New Member

Re: Help, FLASH is read-only

Thanks for the response. New IOS loaded, and routed booted with new IOS Image, many thanks.

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