Allow yaboot bootlader creation even when yaboot.conf is missing (sles11 ppc64 with LVM)

[schabrolles]

Default LVM layout in SLES11sp4 put /boot in LVM (/boot is part of / which is a LV).
In this configuration, LILO does not create /etc/yaboot.conf file. (Yaboot configuration is directly created in the PPC PReP Boot Partition.)

Without /etc/yaboot.conf:

• ReaR ISO DVD is not bootable,
• and bootloader is not re-created at the end of the restoration process.

I propose the following changes to let LILO creates the bootloader even if /etc/yaboot.conf does not exist.

It seems those issues #820 #817 has the problem described here. (Sles11 with default LVM layout => no /etc/yaboot.conf).

[jsmeix]

@schabrolles
many thanks for your valuable contribution to make ReaR
working on PPC64 architecture - it is much appreciated!

By the way:
In
rear/rear.github.com@2d7fe35
I noticed your
http://www.slideshare.net/sebastienchabrolles/relax-and-recover-an-open-source-mksysb-for-linux-on-power

In particular your slide 10
"Linux System Recovery Tools from Distribution."
looks embarrassing - but I think nowadays it is no longer valid
because nowadays at least Red Hat and SUSE provide
Relax-and-Recover (perhaps Ubuntu may not yet provide it?).

[schabrolles]

@jsmeix
Thanks for the feedback.
The Idea of Slide10 was just to tell that Distribution (at the beginning) doesn't create their own tool to recover their system.
They rely on open-source project like ReaR, which is now included in RHEL and SLES (slide14).

But anyway, I will remove this slide10 as it is ambiguous.

[jsmeix]

No need to remove that slide.

But perhaps change it to a more general form so that
it does no longer look as if Red Hat and SUSE are
the bad examples regarding disaster recovery support.

From my experience its basic message is still true
that disaster recovery is not (yet?) a serious topic
for Linux distributions.

Users get whatever fancy features offered in the installer
regardless if that stuff is actually supported by ReaR.

I experience this all the time.

Because of that I wrote sections like
"Let's face it: Deployment via the recovery installer is a must" in
https://en.opensuse.org/SDB:Disaster_Recovery

My ultimate goal is to get ReaR from the rear
onto the driver seat, cf.
"Using rear as generic installer in any installation system" in
https://en.opensuse.org/SDB:Disaster_Recovery

By the way:
Will you attend to FOSDEM?