Please test parallel booting in new sysvinit version

[Petter Reinholdtsen]

The maintenance of sysvinit in Debian are now done by a group working
through alioth, project pkg-sysvinit.  The last weeks I've been
working on the package, fixing quite a few bugs and adding a few
features as well.  The latest version have special handling for
laptops, uses the lsb-base functions for output, support SE/Linux,
have experimental support for parallel booting, and include init.d
dependency information readable by the insserv package.

In short, this is the best version of sysvinit ever, and I would love
to hear some test reports for the parallel booting stuff.

To enable it (be aware that it might break your boot!), insert this
line in /etc/default/rcS:

  CONCURRENCY=shell

This will make the boot script in the sysv-rc package start all init.d
scripts with the save order value for a given runlevel at the same
time, and then wait for all of them to complete.  The output will be a
mess, of course.

Does it work for you?  It works for me, on my test machines.

If it does not work, it is probably because the boot sequence in
debian is broken.  Script depending on each other are started at the
same level, and parallel booting thus break down.  To avoid this
problem, you can use the insserv package.  But it too need correct and
up-to-date dependency information.  Dependency info for several init.d
scripts are included, but I am sure there are more scripts out there.

If information is missing, you can add it directly in the init.d
script in /etc/init.d/, or add override files in
/usr/share/insserv/overrides/ or /etc/insserv/overrides/.  The format
is the LSB init.d comment format, documented on
<URL:http://wiki.debian.net/?LSBInitScripts>.

In the sysvinit source, there is an experimental feature to serialize
the script output (startpar).  This proved to be unstable, and is not
included in the binaries.  It will need more work before it is safe to
use.

When we have correct dependency information in the init.d scripts of
most packages in debian, we can start reordering the default boot
sequence to get maximum speedup due to parallel boot.

And I hope the readahead packages are ready at this time, so we get
the quickest boot in town. :)