Errata Security is an organization of security experts that uses offensive security. Hacker Eye View reports, which cover many topics and actual world situations, provide clients with insights gained through research. A NAS serves the purpose of reliable storage. Disk drives will eventually go out of business. A USB external drive that you use to back up your computer will eventually fail, causing data loss. While it is not likely that your spinning drive will fail tomorrow, it is almost certain that one of them will in the next 10 years. You need something new if you wish to preserve your photos for the rest of your life. RAID is a system that uses redundant disks to ensure data doesn't get lost if one or more fail. Simply buy another disk and continue. It can be used for many years with occasional replacements as failures occur.