Open Stack

Hi, I'd like you to take a look at this patch for potential
DocImpact.
https://review.openstack.org/27034

Log:
commit 4a909b6a51996b0f9b4d6157f4d20d7403cea34c
Author: Matthew Sherborne <msherborne at gmail.com>
Date:   Wed Apr 17 11:05:55 2013 +1000

    Allows VMs to start up properly after host reboot
    
    When a host starts up, it'll check if instances were running before the reboot,
    by looking in the DB. If the instance was, it'll power that instance up.
    
     + Re-adds the 'start_guests_on_host_boot' config option
     + Makes it respect the DB status
     + Updates the nova.conf sample
    
    Flags: DocImpact
    Fixes bug 1169769
    
    Change-Id: I9a8ae76757c32213612e132c223f1466234f1247