You can run "diskutil activity" and find out where all the disks actually came from.
For instance I have a disk4s2 that is actually a Flash installer DMG mounted:
*DiskAppeared ('disk4s2', DAVolumePath = 'file:///Volumes/Adobe%20Flash%20Player%20Installer/', DAVolumeKind = 'hfs', DAVolumeName = 'Adobe Flash Player Installer') Time=20140412-21:05:18.6399
You can run "diskutil activity" and find out where all the disks actually came from.
For instance I have a disk4s2 that is actually a Flash installer DMG mounted:
*DiskAppeared ('disk4s2', DAVolumePath = 'file:///Volumes/Adobe%20Flash%20Player%20Installer/', DAVolumeKind = 'hfs', DAVolumeName = 'Adobe Flash Player Installer') Time=20140412-21:05:18.6399