reboot grub after router crash

Document created by cdnadmin on Jan 25, 2014
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Subject: RE: reboot grub after router crash
Replied by: Joseph Clarke on 13-01-2014 09:49:31 AM
I have never seen this.  Is it possible to capture the "show stack" after the crash as well as the show run, show ver, and show region?  What are you doing that triggers this crash?

In terms of booting out of grub, does the "boot" command not work?

Subject: RE: reboot grub after router crash
Replied by: Joseph Clarke on 13-01-2014 10:31:27 AM
When I interrupt a clean boot, here are my grub "set" parameters:

?=0
color_highlight=black/white
color_normal=white/black
feature_200_final=y
feature_all_video_module=y
feature_chainloader_bpb=y
feature_default_font_path=y
feature_menuentry_id=y
feature_menuentry_options=y
feature_ntldr=y
feature_platform_search_hint=y
grub_cpu=i386
grub_platform=pc
lang=
locale_dir=
pager=
prefix=(hd0,msdos1)/boot/grub
root=hd0,msdos1
secondary_locale_dir=

And the default GRUB config file is:

#------------------------------------------------------------------
# GRUB2 config
#
# Copyright (c) 2013 by Cisco Systems, Inc.
# All rights reserved.
#------------------------------------------------------------------

set timeout=5
set default=0

menuentry 'IOSv: flash0:vios-adventerprisek9-m (hd0,msdos1)' {
    set root='(hd0,msdos1)'
    legacy_kernel '/vios-adventerprisek9-m' '/vios-adventerprisek9-m'
}

Try matching those settings and see if it works for you.
This document was generated from CDN thread

Created by: MARKUS RAINER on 13-01-2014 06:09:25 AM
Hello,
Some parts of our application makes the vIOS router crash. (seems to be a bug in IOS)
Sometimes this ends up in GRUB bootloader console. ("grub>")
Is there a way to restart the router out of  GRUB console manually?

vmcloud netdelete & vmcloud netcreate is not what I am looking for....
thx Markus

Subject: RE: reboot grub after router crash
Replied by: MARKUS RAINER on 13-01-2014 10:03:15 AM
Thanks Joseph for answering.

I already got a Bug ID for that crash: CSCum53360 (crashinfo file is attached to that bug I think...)

The problem when this happens is, that SOMETIMES grub lost it's kernel configuration part when running into that bug.
So a "boot" brings a grub error message (it's something like: configure kernel first...)

After some time playing around with grub I found out how to restart the router:
grub> legacy_kernel /vios-adventerprisek9-m root=(hd0,msdos1)

Then a reboot works fine again.

Also some other parts seem to be missing:
config_directory=(hd0,msdos1)/boot/grub
config_file= (don't exactly know what is missing here)
default=0

A unsolved problem now seem to be that I can't save config:

ronepk1#wr mem
Building configuration...
ronepk1
*Jan 13 14:57:33.375: %GRUB-5-CONFIG_WRITING: GRUB configuration is being updated on disk. Please wait...
*Jan 13 14:57:33.377: %GRUB-3-CONFIG_WRITE_FAIL: GRUB configuration could NOT be written to disk successfully. No automatic GRUB boot image could be determined. Please specify one with boot system

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