How to handle large number of disk devices in "arbitrary" order?

[Carsten Aulbert]

Hi all

first of two questions (second will come later in a separate email).

We have a couple of machines with a largish number of disk drives (currently 
up to 48) plus one or more "flash drives" - could be USB thumb drive, SATA 
disk on module, SSD, whatever. Of course the order in which these are detected 
is not always guaranteed to be the same which makes using setup-storage 
cumbersome and/or impossible to partition/install.

Let's assume a single server for less complexity. 12 hard disks and one SATA 
disk on module (DOM[1]) which should get the OS.

Luckily, here the DOM is usually found as /dev/sda and the disks as sdb..sdm 
thus disk1 refers to the correct device. However, in a different machine with 
a different motherboard another DOM/USB device is the last one.

Our idea as a work-around was to create a symlink to the correct device using 
udev, however FAI dies with an INTERNALL ERROR in setup-storage (invalid 
device /dev/os1 along with a stack trace). From what I found this is because 
/dev/os1 does not match the regexps within the Parser.pm around line 293).

What would be the proper way to address this problem in FAI 3.4.8 if any? 

Ideally, I'd like to end up with a system where I can define any kind of 
mapping for the expected devices per class and FAI picks the correct ones(TM) 
to install the system on and/or create a RAID across...

Anyone with an idea?

Cheers

Carsten

[1] not to be confused with this largish building in FAI-city