Resolve errors after building a server from a saved image
This article shows you how to resolve errors that might occur when you build a
server from a saved image. Most of these errors occur when startup scripts are
not properly configured.
The services that cause these errors are xe-linux-distribution and
nova-agent. The article does not discuss these services in detail, but does
show you how you how to configure these services on startup.
Because these errors are more prominent on Debian®-based servers, the
example troubleshoots an Ubuntu® 13.10 server. The instructions also work
on most other Linux® distributions.
Use the following steps to troubleshoot errors that occur after you build a
server from a saved image:
-
Remove the new server that is experiencing issues and log in to the source
server by using Secure Shell (SSH). The source server is where the original
image was created. -
Run the following command to display the current order of the server's
startup processes:ls -al /etc/rc$(runlevel | cut -d " " -f 2).d/
The output is similar to the following image:
Because this is a new server, nova-agent (
S20nova-agent
in blue in the
image, or s20) is set to start immediately after xe-linux-distribution
(S14xe-linux-distribution
in the image, or s14). However, if you
install certain applications, the installation might reorder the startup
processes and place another service in between S14 and S20. If this
reordering occurs, nova-agent does not start immediately after
xe-linux-distribution. This reordering is what causes the error. -
Move the run levels for these services so that they start up consecutively
and are the first services in theinit.d
startup process. The following
commands move the xe-linux-distribution to S01 and nova-agent to S02:cd /etc/rc$(runlevel | cut -d " " -f 2).d/ mv S14xe-linux-distribution S01xe-linux-distribution && mv S20nova-agent S02nova-agent
Depending on your run levels (which determine how the system starts),
the preceding command varies. Ensure that you use the appropriate numbers
that display in your output. -
Run the
ls -l
command to verify that xe-linux-distribution is set toS01
and nova-agent is set toS02
. -
After you complete these steps, recreate your server image, and then create
the server based on the new, saved image.
Updated 11 months ago