Boyd Stephen Smith Jr. put forth on 3/6/2010 9:11 PM:
1. Old installation using one of more reiserfs file systems.
2. Install Lenny without wiping; use one or more reiserfs file systems.
3. Worst-case scenario file system failure.
4. (reiserfsck --rebuild-tree) -> Links files from the old file system into
the new file system.
If you are going to put reiserfs on a block device, it is not overly cautious
to erase the block device, to avoid (reiserfsck --rebuild-tree) from
performing necromancy.
One more reason not to use ReiserFS. The fact it was created by a convicted
murderer being the big one, obviously.