Correct, the "old" disk now mounted as a usb drive would have a UUID
which would conflict with the "new" system disk.

However, this is easily solved by changing the UUID on the now-usb disk
to something new before your mount it.

  # tune2fs -U random /dev/sdc1

is just one way to do so.

-- 
			       Alec Habig
		     University of Minnesota Duluth
		     Dept. of Physics and Astronomy
			     [log in to unmask]
		   https://urldefense.proofpoint.com/v2/url?u=http-3A__neutrino.d.umn.edu_-7Ehabig_&d=DwIBAw&c=gRgGjJ3BkIsb5y6s49QqsA&r=gd8BzeSQcySVxr0gDWSEbN-P-pgDXkdyCtaMqdCgPPdW1cyL5RIpaIYrCn8C5x2A&m=V1toaJR6UZOrLXFCXkOKFUs3vt3qJ0AfrhAXl8CyADI&s=5WPjGE0HAhpimXd1UWsdnNEXCG9R_Zzq226OaxK_rRo&e=