xen discuss - Jul 2008 - virt-install and booting kernel

All,

Our project has modified the kernel and while testing it with xen, specifically
running virt-install to install a domain, the command hangs when the
install kernel is booting:

# virt-install
What is the name of your virtual machine? dom1
How much RAM should be allocated (in megabytes)? 500
What would you like to use as the disk (path)? /export/home/dom1
How large would you like the disk (/export/home/dom1) to be (in gigabytes)? 10
Would you like to enable graphics support? (yes or no) no
What is the install location?  /net/dhcp-umpk17-227-145/export/home/hostid.iso


Starting install...
libvir: Xen Daemon error : GET operation failed:
libvir: Xen Daemon error : GET operation failed:
Creating storage file...  100% |=========================|  10 GB    00:00   
Creating domain...                                                 0 B 00:07
v3.1.4-xvm chgset ''Tue May 27 23:21:00 2008 -0700
15876:e43193252b89''
SunOS Release 5.11 Version kene-opteron:onnv-fixes:06-14-2008 64-bit
Copyright 1983-2008 Sun Microsystems, Inc.  All rights reserved.
Use is subject to license terms.
DEBUG enabled  |                    <----- HANGS HERE 

To troubleshoot, is there a mechanism to pass boot flags to the
Solaris kernel that is started in this new domain (for domain creation, not
after it is created).  We are trying to debug this kernel hang, so would
like to pass in ''-k'' to boot into kmdb.

If this is not possible, any other ideas for debugging a kernel hang in a
domain?
We have tried forcing a crash dump but unable to examine it with mdb.

Thanks,
Margot Hackett Miller
 
 
This message posted from opensolaris.org

On Thu, Jul 03, 2008 at 01:30:19PM -0700, Margot H. Miller wrote:
> DEBUG enabled  |                    <----- HANGS HERE 
> 
> To troubleshoot, is there a mechanism to pass boot flags to the
> Solaris kernel that is started in this new domain (for domain creation, not
> after it is created).  We are trying to debug this kernel hang, so would
> like to pass in ''-k'' to boot into kmdb.
Run this script:

#!/bin/bash

#usage: domu-boot-flags domname flags

test -n "$1" || exit 1
test -n "$2" || exit 2

virsh dumpxml $1 | grep -v ''bootloader_args'' >/tmp/$1.xml

printf
''/<bootloader>\na\n<bootloader_args>--args="%s"</bootloader_args>\n.\nw\nq\n''
"$2" | ed -s /tmp/$1.xml >/dev/null

virsh destroy $1 >/dev/null 2>&1
virsh undefine $1 >/dev/null 2>&1
virsh define /tmp/$1.xml

> If this is not possible, any other ideas for debugging a kernel hang in a
domain?
> We have tried forcing a crash dump but unable to examine it with mdb.
In the dom0, run:

virsh dump domu-name /var/tmp/crash.dump
mdb /var/tmp/crash.dump

And you can debug as normal, presuming that you''re not hanging *too*
early during boot.

regards
john