Scripted Installation (FAI) vs. System Imaging

[Tim Cutts]

On 27 Sep 2010, at 00:15, Michael Tautschnig wrote:

>> - Documented installation (No "Golden Image")
>>  Fully documented installation from scratch.
>>  No undocumented image tweaks.

... and in fact no need to update the "image" very often at all.

>> - Reproducible installation (No "Nasty Tweaks")
>>  Scripted installation procedure.
>>  Automatically documented.
>> - Tailored Installations (No "Unused Leaks")
>>  Customize installation depending on software requirements.
>>  Customize installation depending on hardware requirements.
>> - Manageable Installations (No "Unknown Redo")
>>  Control, compare and save your installation configurations.
>>  Integrate with configuration management.

Yep, version control is a big one for me.

>> - Secure Installations (No "Virus Reproduction")
>>  No reproduction of security leaks.
>>  Simple update and up to date installations.
>> 
> 
> - A single configuration *for your entire network*. In one of my networks I'm
>  running at least 14 different servers - that would require 14 different
>  images.
> - Softupdates: Changing the configuration does not require reinstallation.

We don't use FAI for configuration management; we use cfengine for that.  FAI we use primarily for hardware detection and installation of a minimal OS - everything else is handed over to cfengine.

The biggest win for it for us has historically been that it's easy to debug, due to the ssh daemon it starts.

We also find that when you're deploying hundreds of nodes, as we do fairly regularly, FAI is a lot less tough on the network than image-based solutions (which we used to use, in the dim and distant past)

Regards,

Tim