[c-nsp] Startup configuration disappears when upgrading code on a Sup 32

[Johnson, Neil M]

We have had an interesting problem upgrading code on Sup 32's.

After we rebooted the supervisor with the new code, the configuration
disappeared. The startup-config file was missing from the nvram file system.
When we took the sup back to our lab we could not recreate the problem. We
opened a TAC case with Cisco and they sent us new supervisor.

Because the TAC was sending us replacement sup's, we were concerned that it
was a HW issue and that we would need to replace all of our remaining sup
32's. So we pressed the TAC for more information.

It is not a hardware problem, but a software problem. The TAC confirmed it
is a known bug: CSCse93511. Unfortunately, the bug is not publicly viewable,
but the name is "Sup32-loses config on upgrade to SXF5." It is a result of a
feature add, which is partially explained in bug case CSCsb72854, which
describes the addition of support for a ROMMON variable (CONFIG_FILE).

Basically, if you upgrade from a code version at or below 12.2(18)SXF4 to a
version at or above 12.2(18)SXF5, you will lose your startup configuration.

Our work around is to visit each switch, set the boot variable to the new
code, back up the startup-config to a file on the sup-bootdisk (or a flash
card), reboot the switch, copy the saved configuration back to the
startup-config, and reboot the switch again.

Interestingly, after you load the new code you can revert back to the
previous version ( < SXF5), go back to the new version, and the problem
doesn't occur.

We hadn't seen anything on the list, so we thought we'd better post it.

(NOTE: We are running the ip lan-only ssh feature set.)

--
Neil Johnson
Network Engineering Group
Telecommunications and Network Services
The University of Iowa
319 384-0938 (Work)
319 330-2235 (Cell)

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/x-pkcs7-signature
Size: 3088 bytes
Desc: not available
Url : https://puck.nether.net/pipermail/cisco-nsp/attachments/20070323/210725f4/attachment.bin