FAQ - Frequently Asked Questions - Knowledge Base

[NT2 U3.1] How to replace a faulty drive in a RAID 1 set?

When a drive fails, the corresponding LED lights up red. If only one drive is defective and the RAID mode is set to RAID 1, the data can still be accessed but we recommend to first backup all data in a different location and then replace the faulty drive immediately. If more than one drive at the same time fails, all data is lost.

Method 1 (Recommended)

  1. Backup all the data from the good drive and store the files in a different location.
  2. Turn off the power and replace the faulty drive.
  3. Turn on the power and connect the USB cable.
  4. Set the RAID mode to "Non-RAID".
  5. Press and hold the confirm button for 3-5 seconds. In the disk management tool (Windows) or disk utility (macOS), the drive will disappear and re-appear again as two disks.
  6. Format the disks as two independent volumes.
  7. Set the RAID mode to "RAID 1".
  8. Press and hold the confirm button for 3-5 seconds. In the disk management tool (Windows) or disk utility (macOS), the drives will disappear and re-appear again as a single disk.
  9. Format the disk.
  10. At this point, you should have a brand new RAID 1 set and you can restore the data from your backup location.

Method 2

  1. Backup all the data from the good drive and store the files in a different location as a secondary backup.
  2. Turn off the power and replace the faulty drive.
  3. Turn on the power and connect the USB cable. The data is mirrored automatically from the good drive. During this process, the HDD LED pulses slowly. The time it takes to complete depends on the drive capacity.

Important

It's always best to keep a copy of your data in a second location. If anything happens to your RAID set, the data gets corrupted or the rebuild fails, you can restore the data from your secondary backup location.

When using the automatic rebuild function, please keep in mind that even if you have stored only a few files on the disk, it might take a whole day to complete the rebuild, because the time it takes to complete depends on the capacity of the drives. For this reason, we recommend using method 1 and starting from scratch.