Sorry for cluttering up the forums if this has been asked before. I haven't had any luck finding info on this. After reading in MANY threads about the reliability of using just one USB stick for the OS I have decided for peace of mind to use 2 and mirror them. When I built the NAS, I did buy two of the exact same USB drives. One for the installer and the other for the install. My question is, can I use the initial USB drive that has the ISO installer on it for the 2nd drive for the mirror or do I need to keep that in case I need to reinstall in the future? If I can use it, do I need to wipe it first or will it just be written over when I create the mirror in System > Boot > Status?