Fedora: FC2 <- FC3 fs incompatibilities

[Klaus-Peter Schrage]

Recently I did a fresh FC3 install - not an upgrade of FC2, as, since 
RedHat.wayback.when, I always keep two subsequent OS versions on my box 
to boot into them through Grub. And I always have the old '/'-partition 
in my new /etc/fstab (and vice versa) to compare how things are done in 
the old/new configurations.

After the FC3 install had finished and after some post-install fiddling, 
I tried to boot into FC2, but during the fsck part of the boot process, 
I got a message like:
	fsck.ext3: Filesystem has unsupported feature(s) (/)
	e2fsk: Get a newer version of e2fsk!
and I ended up in a maintenance console. From there, I followed the 
advice,  installed the e2fsprogs-1.35-11.2 RPM from the FC3 DVD and 
rebooted into FC2, where the debacle began:

To make it short, it ended up in a completely hosed FC2 '/'-partition 
with bunches of file fragments in lost+found!

I'm sure I did something extremely stupid, but even with extensive 
googling I didn't get many clues:
http://bugs.gentoo.org/show_bug.cgi?id=71159
http://www.redhat.com/archives/fedora-list/2004-November/msg02853.html

What is clear now: There has been added the feature of online growing of 
  existing ext3 file systems to e2fsprogs. It is faintly described in 
the FC3 release notes, but even if I had read them before ;-), I 
wouldn't have read a warning out of it. This new feature may be or may 
be not the cause of the loss.

Thanks god, I didn't loose important data ...

Klaus