FAQ - Frequently Asked Questions - Knowledge Base

[Thunder2 Duo Pro] Can I use RAID 1 with just one disk?

No, we do NOT recommend installing only one disk when the RAID mode is set to RAID 1. Otherwise, if a second disk is installed in the future, the system will automatically start to rebuild the data from HDD A about 40 seconds after the second disk has been installed. If the disk with the data happens to be in position for HDD B, all data would be overwritten with the blank disk, therefore erasing all data.

In addition, rebuilding a RAID array bit by bit takes a long time, so it's much better and faster to create a new RAID 1 set with two disks and only then copy the data onto the disks.