FAI of custom linux OS

[Tim Cutts]

On 15 Jan 2010, at 2:18 pm, Thomas Lange wrote:

>>>>>> On Fri, 15 Jan 2010 13:48:41 +0000, Tim Cutts  
>>>>>> <tjrc at sanger.ac.uk> said:
>
>> use VMware, and although I can install these using FAI, it's faster
>> and simpler to use the templating mechanism that ESX has.  FAI's  
>> great
>> strength for me is the ability to deal with divergent hardware, and  
>> of
>> course that isn't an issue with virtual machines.
> FAI also simplyfies the handling of different configurations, for
> e.g. if you have to install database servers, desktops, and a bunch of
> slightly different web servers.

I handle all that stuff with cfengine, rather than with FAI.  For me,  
FAI configures the hardware and a basic OS install.  We also make FAI  
create udev rules so that the network interfaces look the same  
regardless of the physical hardware, so that cfengine refers to  
network interfaces by functional names like 'site', 'heartbeat',  
'lustre' or whatever.  cfengine does all role-specific configuration.   
This is because there are plenty of systems around here which still  
need automatic configuration but which are not installed with FAI  
(SLES10, Red Hat, Solaris etc).  To avoid duplication of configuration  
data, our installation systems are never set up to do anything special  
according to the machine's purpose.

> If I understand the template feature in ESX correctly, it's only a
> cloning operation. You can just clone an existing virtual machine. But
> you can't clone onnly part of a configuration or modify some parts
> after cloning.

Actually, you can, but the extent to which you can rather depends on  
the OS being deployed.  If the OS is Debian, it doesn't do a very good  
job.  :-)  If you, like me, also have to run Windows VMs, there are  
quite sophisticated things you can do with VMware Converter, such as  
mess around with disk layouts, change which services are running in  
the clone machine, change the network interfaces, and so on and so  
forth.  It's nowhere near as sophisticated as FAI or cfengine, of  
course, but it's quite useful nevertheless.

Regards,

Tim


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