Error in setup-storage in FAI 4.1

[Thomas Neumann]

Hello

On Monday 26 May 2014 11:00:29 Andreas Heinlein wrote:
> I'd like to ask again if there has been any progress with getting
> setup-storage to work with LVM again? Following my bug report (#740929)
> from March, there has been a response but so far I found no solution
> which works for me.

'Officially' there seems to be no progress at all.

'Inofficially': I have by now started (and scrapped) my 6th attempt to do some 
improvement on the existing setup-storage. As you have already noticed not 
only setup-storage but also the underlying Linux::LVM is pretty seriously 
broken. (Roland's patch does work, but I'm not sure if it's really the 
'correct' fix.) However it's hard to do anything with the code because 
everything is very tightly coupled together in setup-storage and there are no 
existing unit tests - neither for setup-storage nor Linux::LVM. The reason for 
the multiple attempts is that I try to change some small thing but it quickly 
escalates into multiple changes in multiple locations. These changes ~should~ 
be safe, but I have no chance at all to verify them - except by installing 
actual clients and testing every possible combination of OS, kernel, tools, 
disk_configs, ... 

What can be done is to apply some patch and cross fingers it doesn't break 
anything else. I'm really uncomfortable to do this kind of work, because it 
might break somebody else's setup.


@Thomas L.: What do you think about introducing something like the 
USE_SETUP_STORAGE variable again? This way it would be possible to provide the 
'working-but-broken-LVM' and an 'experimental' version of setup-storage. If a 
client type doesn't need LVM, then stay with the old s-s and avoid possible 
breakage, if LVM is required then it's broken anyway and it does not really 
matter to possibly add an additional bug.

Important stuff that needs to be fixed:
 - setup-storage must properly recognize and wipe existing LVM-volumes
 - either Linux::LVM or setup-storage must be aware of the changes in 2.02.85 
and 2.02.95(?) and properly handle them

Important feature requests:
 - setup-storage should be able to configure btrfs volumes (at least root 
volumes, subvolumes would be nice too)


btrfs root volumes should be pretty straightforward. I haven't thought about 
how to integrate sub-volumes into the existing syntax.

bye
thomas