evbarm build using exorbitant disk space during build

[Martin Husemann <martin%duskware.de@localhost>]

Houston, we have a problem:

the evbarm build uses up enormous amounts of temporary disk space:

$DESTDIR is 602 MB
$OBJDIR is 11.4GB
$RELEASEDIR is 2.6GB

Most of the space in $OBJDIR is used for kernel builds (> 6GB) and also for
the cdimage.

Now why is this a problem? Most nodes on the build cluster have a 16GB
limited tmpfs space for this, so the evbarm builds only suceed, if they
are run on one of the other nodes. Unfortunatley exactly those nodes
are scheduled for replacement, and the new, faster ones will have the
16GB limit as well.

There is an admin ticket and options are being discussed, but the easy 
solutions at the admin level will slow down all our other builds - or
would be just stopgaps untill space runs out again.

So, a solution at the build system level might be better (but I don't see
any easy one).

Or we drop all the INSTALL kernels and implement some hacks to load the
install file system as a module.

Personally I have (I think) never used an install kernel on some evbarm
device, but instead used NFS root and manual install or similar schemes.

Any smart ideas?

Martin