Libguestfs - Apr 2012 - Cannot login after modification shadow file with guestmount

Hi.


I have a VM with CentOs6.2 on KVM.   I mount an image of the VM when it's
not working with guestmount:

root at diehard:~# guestmount -a named-centos.img -i tmp

vi /etc/shadow

insert comment line into the file (esc yy p 0 i # esc :wq!), save changes,
unmount the image, turn on the VM, and I cannot login.

I cannot login even if I recover the shadow file.

root at diehard:~# guestmount --version
guestmount 1.16.15


-- 


?????? ?????? ?????????
Daneel S. Yaitskov


skype: daneel_s_yaitskov
google talks:  rtfm.rtfm.rtfm at gmail.com
email: dy at hivext.net
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://listman.redhat.com/archives/libguestfs/attachments/20120420/1605f3c5/attachment.htm>

On Fri, Apr 20, 2012 at 05:48:06PM +0400, Daneel Yaitskov
wrote:
> I have a VM with CentOs6.2 on KVM.   I mount an image of the VM when
it's
> not working with guestmount:
> 
> root at diehard:~# guestmount -a named-centos.img -i tmp
> 
> vi /etc/shadow
Hopefully you edited the guest's tmp/etc/shadow, not your host's
/etc/shadow ...
> insert comment line into the file (esc yy p 0 i # esc :wq!), save changes,
> unmount the image, turn on the VM, and I cannot login.
> 
> I cannot login even if I recover the shadow file.
Not much information to go on here, but my guess is that /etc/shadow
has the wrong permissions or SELinux context after you edited it.

We recently fixed this bug in virt-edit:
https://bugzilla.redhat.com/show_bug.cgi?id=788641
but that doesn't help you if you're using guestmount.

These are what they should be on a RHEL 6 system:

  $ ll -Z /etc/shadow
  ----------. root root system_u:object_r:shadow_t:s0    /etc/shadow

If that doesn't help, have a look for the error (/var/log/messages,
/var/log/secure, or /var/log/audit/audit.log):

  $ guestfish --ro -a named-centos.img -i
  ><fs> less /var/log/messages
  [etc]

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://et.redhat.com/~rjones/virt-df/