Buffalo HS-D300GL User Manual page 59

Disk Scan Type: The Disk Scan Type pull-down menu allows you to select whether the Disk Scan
is to be a Normal or a Thorough scan. A Normal scan is a fast disk scan. The Thorough Scan will
scan every sector individually. The Thorough Scan can take up to several hours to complete. It is
recommended that you not access LinkStation or turn LinkStation off during a Thorough Scan.
Maintenance Settings - Disk Scan
Disk Scan: The Disk Scan Target is the disk
that is to be scanned. The Internal HDD option
is for LinkStation's internal hard drive. If a
USB Hard Drive is connected to LinkStation,
then it will also be available from the pull-down
menu. Please select the disk that should be
scanned. If both disks are to be scanned, then
the Disk Scan must be run twice; once for each
disk.