Device-Harddisk2-DR2 error

Source
Imminent failure on 'Harddisk2\DR2'
I have seen these paths end with three things after Harddisk#\, DR#, Partition# and FT#.
DR is simply an abbreviation for Drive and should match the Harddisk# entry in the path before it.
Partition# indicates the partion on that drive
and FT#, where FT is an abbreviation for Fault Tolerance set, indicates the Fault Talerance set the drive belongs to.
Since your is simply "\Device\Harddisk1\DR1" and "\Device\Harddisk2\DR2" both the Harddisk# and DR# represent the same as the Disk # you see in Disk Management.