PS D:\> chkdsk
The type of the file system is NTFS.
Volume label is 2TBRaid1Backup.
WARNING! F parameter not specified.
Running CHKDSK in read-only mode.
CHKDSK is verifying files (stage 1 of 3)...
109568 file records processed.
File verification completed.
1 large file records processed.
0 bad file records processed.
0 EA records processed.
0 reparse records processed.
CHKDSK is verifying indexes (stage 2 of 3)...
71 percent complete. (108789 of 121916 index entries processed)
An index entry from index $O of file 25 is incorrect.
Missing object id index entry or duplicate object id detected
for file record segment 3.
121916 index entries processed.
Index verification completed.
Errors found. CHKDSK cannot continue in read-only mode.