====== The Gandi agent and server configuration files ======


===== The role of the Gandi agent =====
In expert mode, the Gandi configuration agent is tasked with receiving information about server parameters, number of cores, RAM, new disk size, disks to be attached or detached, and so on.

<note important>
This agent is included in the ''gandi-hosting-vm2'' package, which may need to be updated in order to take advantage of the latest improvements.

To do this, use the command 'aptitude install gandi-hosting-vm2'. 
</note>


===== Gandi config files =====

<note>
Certain files are required by the virtual server due to the particularities of our hosting infrastructure.
</note>

Several files and directories are available to you for the purposes of adapting your expert server to your needs.

==== /etc/gandi ====

This directory contains our configuration scripts.

==== /etc/default/gandi ====

In this file you can adjust the following parameters:

  * choose between short hostname or FQDN
  * create/activate swap at boot
  * change the MOTD for SSH connections
  * change the time zone
  * activate/deactivate specific Gandi system options (''sysctl'')
  * add/remove Gandi SSH keys to grant or revoke our access
  * change SSH options (''Compression'', ''PermitRootLogin'', ''EmptyPasswords'')
  * update (or don't update) ''/etc/resolv.conf'' via DHCP
  * automatically configure the emergency console
  * activate/deactivate PAM changes for root access
  * activate/deactivate automatic hostname configuration
  * activate/deactivate automatic DNS server configuration
  * change data disk mount options and default mount locations

<note info> For RPM-based distributions, this file is located at :

  /etc/sysconfig/gandi
</note>

==== /etc/udev/rules.d/86-gandi.rules & /etc/fstab ====
You have two ways of mounting disks on your virtual server:

  * **''udev'' (default)**

By default, ''udev'' takes care of automatically mounting data disks on ''/srv/'' with the name of the disk. For example, a data disk named ''d_data'' would be mounted at ''/srv/d_data/''.

  * **''fstab'' (udev deactivated)**

If you want to specify your own mount points, you must deactivate the ''udev'' rules related to the disks in the file ''/etc/udev/rules.d/86-gandi.rules'' (the VPS will need to be rebooted in order for changes to this file to take effect).

<note tip>
The two lines that need to be commented out to deactivate udev are :

  SUBSYSTEMS=="xen", DRIVERS=="vbd", SUBSYSTEM=="block", RUN+="fake_blkid -o udev -p $tempnode", RUN+="/etc/gandi/manage_data_disk.py", OPTIONS+="last_rule"
  SUBSYSTEM=="block", ENV{DEVTYPE}=="disk", ENV{ID_VENDOR}=="gandi.ne", RUN+="fake_blkid -o udev -p $tempnode", RUN+="/etc/gandi/manage_data_disk.py", OPTIONS+="last_rule"
  
</note>


==== /etc/init.d/gandi-mount & /etc/init.d/gandi-kernel ====

  * ''gandi-mount''

This script allows disks attached to the server and present in ''/proc/partitions'' to be mounted on ''/srv/''.

  * ''gandi-kernel''

This script automates the installation of kernel modules.

<note>
Be sure to update your Gandi packages regularly using the mirrors of our servers to benefit from the latest improvements.
</note>