FAQ - Frequently Asked Questions - Knowledge Base
[NT2 U31C] Why are both HDD lights flashing when transferring files only to one disk?
When using Non-RAID and transferring files to only one disk, the LED lights for both disks will be flashing to indicate disk activity. This is due to the hardware design of the NT2 U31C and it's an expected behavior. The data is written only to one of the disks but whenever there is disk activity, both lights will be flashing.