Ubuntu natty setup-storage questions

[Andreas Sindermann]

Thomas Neumann writes:
 > > b) I'm currently using two classes NO_SCRATCH (for a standard partition
 > > layout that all of the FAI clients are using) and SCRATCH (to preserve a
 > > possibly existing /scratch partition that I created by hand earlier on
 > > some of the FAI clients, but not on all of them).
 > >
 > >    b 1) How could theses classes NO_SCRATCH and SCRATCH be merged in one
 > >         single class? Is it possible at all?
 > 
 > What is your goal?
 > 
 > a) Do you manually decide which class applies for each host and want to
 > automate/simplify the decision process?
 > 
 > b) Do you want to clean up/consolidate your config space and want to
 > handle /scratch as a special case of NO_SCRATCH?
 > 
 > The answers would be different. a) would hint at some decision logic in
 > class/ which automatically announces the correct class. b) would require
 > either modifying your layout-files on the fly or change the way
 > disk_config works.
 > 
 > Everything's possible. We just need to find the right hammer for your
 > nail. ;)
 > 

Currently I'm using the following script to decide whether a client
does already have a scratch-partition or not:

root$ cat <FAI>/class/30-detect-scratch-partitions
#! /bin/bash
# detect whether a scratch partition /dev/sda3 already exists
size=`fdisk -s /dev/sda3 2>/dev/null`
if [ ! -z $size ]; then echo "SCRATCH" ; else echo "NO_SCRATCH"; fi
exit 0


I'd prefer a single setup-storage layout file that automagically
detects and preserves an already existing partition. It seems that
the current setup-storage

a) changed behaviour concerning cylinder boundaries compared to
   setup_harddisks 

b) offers different methods how to preserve partitions, but none of
   them seems to fit my case (or I misunderstood the manual, that
   might be the case, of course...).

c) gives a simple error, which should not happen. Or my layout file
   has an error that I don't understand...


Andreas