I have an external SATA drive bay setup with a RAID 10 configuration. The devices manager is saying I need to rebuild drive 3 and drive 1. I have data on the drive that has not been backed up. If I rebuild the two drives, will data be lost?
In RAID 0+1, if the volume is still usable then you haven't lost any data (yet) and rebuilding the drive shouldn't cause any harm. But being paranoid with RAID systems is a healthy attitude and I'd back up all my data before doing anything.
It's a really good idea to test these kinds of scenarios BEFORE committing your data to a RAID set so you understand what to do when the inevitable glitches arise.