disk recovery problem(s)

[Robert Huff]

	Had a power outage recently; when trying to fsck several
external hard drives I'm getting unexpected errors.
	For example:

huff@>> fsck /dev/da3a
** /dev/da3a
** Last Mounted on /backup
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
ROOT INODE UNALLOCATED
ALLOCATE? [yn] 

	a) what's probably happened?
	b) is there a way to recover the data?  I can scrub the disk
and restore, but would like to avoid that if at all possible.


					Robert Huff