View source for Installing a VServer guest with debootstrap and softupdate

Many people don't use the -m fai VServer build method (maybe because it's broken?) but build their VServer guests without FAI, using debootstrap or any other standard method. A guest installed like that will now nothing about FAI, so in order to turn it into a FAI install client, some manual extra steps are necessary at least once. There are also some pitfalls.

= The guest cannot NFS mount by default =

For security reasons, the defaults do not allow a VServer guest to perform NFS mounts. In case your FAI config space lives on a separate physical server and therefore needs to be mounted through NFS, this will lead to a <tt>permission denied</tt> error.

To fix this problem, on the VServer host, create a file called

<tt>
/etc/vservers/<vserver>/bcapabilities
</tt>

with the following content:

<code>
CAP_SYS_ADMIN
</code>

If your VServer guest was already running, make sure to re-start it for these settings to become effective. (Q: Would there be a parameter to set this at guest build time???)

= You need a FAI client on your guest =

Before you can do anything else, you will need to install the fai-client package:

<pre>
aptitude install fai-client
</pre>

= The FAI client needs to know about your config space =

In the file <tt>/etc/fai/fai.conf</tt> look for the line:

<pre>
#FAI_CONFIG_SRC=nfs://yourserver/$FAI_CONFIGDIR
</pre>

Uncomment this line and replace <tt>yourserver</tt> with the hostname of the sevrer that is exporting your config space via NFS.

= The guest does not have enough space in /tmp by default =

By default, a VServer guest mounts /tmp to a ramdisk with 16 MB of RAM. This will cause the updatebase step of FAI to stall because it tried to write more than 16 MB to a file in /tmp. There are a number of ways to solve that problem, such as

 * Unmount /tmp, so it will use the filesystem, not the ramdisk.
 * Increase the available space in /tmp.
 * Set the variable TMPDIR to something else, for example using a VSCHILD.var file in your config space.

<pre>
TMPDIR=/var/tmp
</pre>


= The guest does not yet have any FAI classes =

Make sure to run

<pre>
fai softupdate -N
</pre>

as the <tt>-N</tt> option will make sure that the class detection for your VServer guest is done from scratch. Without the <tt>-N</tt> option, you will just see an error message saying that <tt>/var/log/fai/classes</tt> was not found.