Using compact flash disk

[wilson_1234_2]

I have a new 7206 router that I will put in place soon.

In the meantime, I would like to take the opportunity to experiment with using the flash disk.

I have looked at the document on Cisco's site, but it is very basic.

I have a couple of questions:

1. My understanding is the boot image can be on onboard flash or the compact flash and by default the router will check on board flash first, then the compact flash, is this correct?

2. What are the most common usage for the flash disk?

3. Below is from another 7206 in production:

7206VXR#sh bootvar

BOOT variable = disk0:c7200-jk9o3s-mz.123-14.T7.bin,12;

CONFIG_FILE variable does not exist

BOOTLDR variable does not exist

Configuration register is 0x2102

7206VXR#sh flash

Open device slot0 failed (No such device)

It looks like there is no onboard flash on this router and everything is located on disk0:

7206VXR#dir

Directory of disk0:/

1 -rw- 1807 Jan 20 2005 21:20:58 -05:00 home.shtml

2 -rw- 26792036 Apr 03 2006 13:32:22 -04:00 c7200-jk9o3s-mz.123-14.T7.

bin

3 -rw- 93095 Jan 20 2005 21:20:58 -05:00 attack-drop.sdf

4 -rw- 270848 Jan 20 2005 21:21:00 -05:00 home.tar

5 -rw- 1187840 Jan 20 2005 21:21:02 -05:00 ips.tar

6 -rw- 3885056 Jan 20 2005 21:21:10 -05:00 sdm.tar

7 -rw- 1463 Jan 20 2005 21:07:42 -05:00 home.html

4. Did anything have to be done to this router for the router to boot (other than modify bootvar) or is this default behavior?

5. What is the upgrade procedure if I need to put an upgrade image larger than what this disk can hold?

[wilson_1234_2]

Sundar,

After looking at the new 7206 as opposed to the existing 7206(that probably has had changes made) I have a couple of questions regarding the differences between the two:

The new router has an image in bootflash and the exiting router does not.

I see the exising router just has an entry in the config file:

Existing router

boot-start-marker

boot system disk0:c7200-jk9o3s-mz.123-14.T7.bin

boot-end-marker

And the new router does not:

New router

boot-start-marker

boot-end-marker

What is the "kboot" image doing?

With no entry in the "boot-start" and "boot-end" markers, does the router need the "kboot" image?

Is this a needed file if you modify the config with boot variables?

Can you just arbitrarily remove the file from bootflash and make modifications like this?

If the boot image is small enough, can you put it in the bootflash and designate that as the boot location?

[sundar.palaniappan]

Richard,

See the response(s) inline.

""What is the "kboot" image doing?""

It's a boot image. I know the boot image was required with most older IOSs but I thought the newer IOSs came integrated with the boot image and didn't require one. I am not sure whether the kboot image is currently being used by your new router or not. If you do a show version, it should say somewhere on top, what boot image is being currently used and check whether c7200-kboot-mz.123-15 is being used.

""With no entry in the "boot-start" and "boot-end" markers, does the router need the "kboot" image?""

Since it's in the bootflash no boot statement is required the router would automatically use the boot image. Instead if it was on external storage (disk0) then it wouldn't have been used without a boot statement in the configuration. If in the show version you don't see the boot image (12.3-15) being used then you can move it over to disk0 (to be safe) and delete it from the bootflash.

""Is this a needed file if you modify the config with boot variables?""

If the boot image is currently being used then you can move it to disk0 and use the boot system commands to point to disk0 and you would also need a boot system command for the actual IOS pointing to the appropriate location where the OS is stored.

""Can you just arbitrarily remove the file from bootflash and make modifications like this?""

You can certainly move the files. As I said before before deleting any file make a copy of it and store in disk0, just in case you need it later.

""If the boot image is small enough, can you put it in the bootflash and designate that as the boot location?""

Yes, as stated in the earlier response.

Here's a link about boot images in a 7200.

http://www.cisco.com/en/US/docs/routers/7200/install_and_upgrade/7200_boot_image_info/3876b.html#wp38148

HTH

Sundar

[wilson_1234_2]

Sundar,

The new router is using the the boot image:

test_router_new#sh ver

Cisco IOS Software, 7200 Software (C7200-IS-M), Version 12.4(12c), RELEASE SOFTWARE (fc1)

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

Copyright (c) 1986-2007 by Cisco Systems, Inc.

Compiled Fri 13-Jul-07 09:55 by prod_rel_team

ROM: System Bootstrap, Version 12.2(4r)B4, RELEASE SOFTWARE (fc1)

BOOTLDR: 7200 Software (C7200-KBOOT-M), Version 12.3(15), RELEASE SOFTWARE (fc3)

test_router_new uptime is 1 hour, 54 minutes

System returned to ROM by power-on

System restarted at 18:56:46 UTC Mon Apr 14 2008

System image file is "disk0:c7200-is-mz.124-12c.bin"

The older router is not:

7206VXR#sh ver

Cisco IOS Software, 7200 Software (C7200-JK9O3S-M), Version 12.3(14)T7, RELEASE SOFTWARE (fc2)

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

Copyright (c) 1986-2006 by Cisco Systems, Inc.

Compiled Thu 23-Mar-06 04:43 by pwade

ROM: System Bootstrap, Version 12.2(4r)B2, RELEASE SOFTWARE (fc2)

7206VXR uptime is 36 weeks, 4 days, 7 hours, 51 minutes

System restarted at 09:00:14 EDT Thu Aug 2 2007

System image file is "disk0:c7200-jk9o3s-mz.123-14.T7.bin"

So, are you saying the router HAS to have the kboot image installed somewhere in order to boot, unlike the older router?

Also, if I modify the boot variable in the router, does the boot image and the ios have to reside in the same place?

[sundar.palaniappan]

From CCO

""One of the purposes of the BootImage is to act as a backup image in case the system fails to load up any of the specified (by default or via the configuration) IOS images. The backup image could then download a new IOS image to any of the PCMCIA slots. The other purpose of the BootImage is to help boot the system directly from a network server. For these reasons, the BootImage is developed with support for just the IP protocol and a few core IP features. This helps maintain a small and stable image that indirectly also helps in the bootup time.

The requirement of being able to boot or download an IOS image over any network interface using the BootImage has led Cisco to add the support drivers for every new Cisco 7200/uBR7200 supported network modules to the Cisco 7200/uBR 7200 BootImage. These drivers have made the BootImage outgrow the available space in the FLASH SIMM (on the I/O controller) used to store the BootImage. here is no technical requirement to match the version release of the boot image to the version release of IOS. One possible workaround for this issue involves selecting a boot or kboot image file that is not of the same release as the IOS version loaded on the router.""

As you can see from the above explanation the existing router isn't using a boot image whereas the new one does and the boot image provides the backup option should the IOS becomes corrupt or lost in restoring a valid IOS image.

""Also, if I modify the boot variable in the router, does the boot image and the ios have to reside in the same place?""

No. Just make sure your boot statements point to the appropriate location of the file. Let's say you have both images in disk0 you would use a configuration like this.

boot bootldr disk0:c7200-kboot-mz.123-15.bin

boot system disk0:c7200-is-mz.124-12c.bin

HTH

Sundar

[wilson_1234_2]

Sundar,

So basically the boot image is a lower functioning image that sort of acts as a backup and allows suuport for all drivers.

Cisco is basically doing what josephdoherty said he does:

"I've often loaded an older or reduced feature set IOS that fits on the internal flash and run the current IOS from external flash. This often then allows a "backup" IOS if something goes wrong with the current external version. (Often much nicer to deal with than ROMMON.)"

Excellent lesson on the use of flash in general.

Thanks

[sundar.palaniappan]

Richard,

Yep, I learned something today as well while researching this for you. Joseph has made a very good suggestion about storing a limited feature set IOS image that would fit in the bootflash for backup purposes. However, I believe the boot image would help only in restoration of IOS and not handle routing of user traffic.

BTW, thanks for all the ratings :-)

HTH

Sundar

[wilson_1234_2]

You bet Sundar,

I have not forgotten the other question I was going to ask you, but have not had a chnage to put it together just yet.

Thanks for all the great answers to my questions.

[wilson_1234_2]

Sundar using the limited feature set image as a secondary, if the router boots to the backup image if there is a problem with the main image,

Does it use the same config but just has a limited feature set?

Like maybe ipbase with the same ethernet and serial config?

[sundar.palaniappan]

Yes, the configuration should be the same. The router would attempt to boot from the first image specified in the boot system command and if it can't load that image then it should move down the list and boot from the second image and so on.

HTH

Sundar

[Joseph W. Doherty]

fyi: If you boot into "backup" IOS, that's with limited features vs. the "normal" IOS, it will process the startup-config but may not support everything in it. This may not be a critical problem except if it doesn't understand something like the routing protocol you're using. Also, must be careful about saving the running-config while the "backup" IOS is running, as it will update the startup-config without the not understood config lines.

[wilson_1234_2]

Excellent suggestion,

Thanks.