When a duplicate block is found in the filesystem, the filesystem is rescanned to find the inode that previously claimed that block. When the duplicate block is found, the following informational message appears:
B DUP I=IInode I contains block number B that is already claimed by another inode. This error condition generates the
BAD/DUP
error message in Phase 2.
You can determine which inodes have overlapping blocks by examining
this error condition and the DUP error condition in Phase 1.