Buffalo NAS Drives are Formatted to XFS.
From the Manual,
Note that FAT32 has a 2 gigabyte fi lesize limit
for individual fi les. If you choose FAT32 for your
fi le system, you will not be able to store single
fi les larger than 2 gigabytes on the drive. Use of
the XFS or EXT3 fi le systems is recommended.
Press Select Target Disk when done.