How do I know if data is stored on USB?

I have used Datamine 2 for a few days.
At first I hade everything up and running.
Now I have this info under settings:

Channels Disk Space Total (kb)
Disk Space Used (kb)
Disk Space Free (kb)

How do I know if data is stored on USB?

I am using the following settings:
SetDataDirectory = /dataMine/
SetManualMount = 0
diskTotal = 7537536
diskUsed = 1648
diskFree = 7535888
SetMountUUID = 0CE3-4927
SetMountPoint = dev/sda1
mountLocation = dev/sda1
mountType = vfat