I worked out how to do it and got these results but what does it mean?
[root@localhost guest]# fsck -f /dev/hdb6
fsck 1.41.6 (30-May-2009)
e2fsck 1.41.6 (30-May-2009)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/hdb6: 166199/909312 files (1.1% non-contiguous), 1322452/3634698 blocks