WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

Re: [Xen-users] resetting lost root password on a xen guest

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-users] resetting lost root password on a xen guest
From: Liam Kirsher <liamk@xxxxxxxxxxx>
Date: Tue, 30 Oct 2007 10:50:34 -0700
Delivery-date: Tue, 30 Oct 2007 10:56:26 -0700
Domainkey-signature: a=rsa-sha1; b=P6CqQaKYQ510YWnB1kJnPZuvhlHIjFjYUuLOpx+GRDEhayUFBxL/vXa97eZW83imp8Q0oiugx5XZPHTNSbnLt6Vcyl6PyZaEHVkOpkOx07sUBOX4oCpXFis/6J331Y+2BYA89+hlgBOouYrw5/+fDANL/jwTgJ52AI51DScqBD4=; c=nofws; d=numenet.com; q=dns; s=selector1
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <Pine.LNX.4.64.0710301034370.7474@xxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
Openpgp: id=7011F7B7; url=http://liam.numenet.com/pgp/
References: <4C403314-E476-43CC-B679-AC1F6F799896@xxxxxxxxxxxxxxx> <Pine.LNX.4.64.0710301034370.7474@xxxxxxxxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird 2.0.0.0 (X11/20070326)
Steven, why do you write "being sure to fsck it afterwards" ? Is that
important?
The reason I ask is that I had a domU filesystem get corrupted, and I
don't know how it happened.
It was not all that important in that it was easy to recreate, being
just my stock CentOS 5 template + bind.
But, just the same, I'd like to know how it happened!  Interestingly,
Xen never had a problem creating the domU.  However, my attempts to
mount it (after shutting down the domU) failed because mount couldn't
find a valid ext3 filesystem.  Eventually I found a valid superblock,
but virtually all the files ended up in lost+found.

Steven Timm wrote:
> Darren--can you temporarily stop the xen guest and mount
> its root FS from dom0? if so, then just zero out the root passwd
> and shadow entry from there, unmount the client rootfs, being
> sure to fsck it afterwards, then start up the client again.
>
> Steve
>
>
> On Tue, 30 Oct 2007, Darren Jacobs wrote:
>
>> Hi All,
>>
>> I need to get into a xenguest running linux for which the root
>> password has been lost.  I'm running xen 3.0.3 under RH 5.
>>
>> I'm trying to figure out how to get pygrub for this guest to load up
>> the typical "init=/bin/sh" to get the console to come up at the
>> command line prompt so I can reset the root password.
>>
>> Trolling though google I've see suggestions to add args =
>> 'init=/bin/sh' or opts = 'init=/bin/sh' to the guest configuration
>> file.  None of them appeared to have worked.  If I do a 'xen create
>> echo11 -n' after making any of the above file mods I see that the
>> args were not modified:
>>
>> -- 
>> (vm
>>   (name echo11)
>>   (memory 500)
>>   (on_reboot restart)
>>   (on_crash restart)
>>   (vcpus 1)
>>   (uuid cb855323-2867-b84a-d766-32a39d252bb7)
>>   (bootloader /usr/bin/pygrub)
>>   (image
>>       (linux
>>           (ramdisk /var/lib/xen/initrd.kIQYUw)
>>           (kernel /var/lib/xen/vmlinuz.Xwl81-)
>>           (args 'ro root=/dev/VolGroup00/LogVol00')
>>       )
>>   )
>>   (device
>>       (tap (uname tap:aio:/var/lib/xen/images/echo11) (dev xvda)
>> (mode w))
>>   )
>>   (device (vif (bridge xenbr0) (mac 00:16:3e:69:69:90)))
>> -- 
>>
>> So I tried to bring the guest up manually from dom0 with " pygrub
>> /var/lib/xen/images/echo11.dsk".  When the menu comes up I edit the
>> kernel line directly and insert "init=/bin/sh".  You can see below
>> that the init statement was indeed read:
>>
>> -- 
>> [root@dom0 xen]# pygrub /var/lib/xen/images/echo11
>> Going to boot Fedora (2.6.20-2925.13.fc7xen)
>> kernel: /vmlinuz-2.6.20-2925.13.fc7xen
>> initrd: /initrd-2.6.20-2925.13.fc7xen.img
>> linux (kernel /var/lib/xen/vmlinuz.pBqWti)(ramdisk
>> /var/lib/xen/initrd.9IdU7X)(args 'ro root=/dev/VolGroup00/LogVol00
>> init=/bin/bash')
>> [root@dom0 xen]#
>> -- 
>>
>> However the guest did not start up :'(  Its starts just fine if I
>> issue a "xm create echo11".  Any suggestions on where to look from here?
>>
>>
>>
>

-- 
Liam Kirsher
PGP: http://liam.numenet.com/pgp/


_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users