Creating large files can result in non-allocated blocks:
⋊> ~/m/p/project3 on fsck ⨯ ./mkfs filesys.dat 2048 2048
⋊> ~/m/p/project3 on fsck ⨯ python -c 'print("xy" * 15 * 2048)' | ./tee /bigfile >/dev/null 19:38:13
⋊> ~/m/p/project3 on fsck ⨯ ./fsck 19:38:16
error: inode 0 has 1 links but nLinks is set to 3
error: block 12 is not mentioned in inodes but is marked as allocated
Creating large files can result in non-allocated blocks: