I'm setting up a Debian file and media server with a 1TB NVMe drive for the operating system and services, plus two 14TB drives for storage. I'd like to use one 14TB drive to periodically back up the other, but I don't want the backup process to affect server performance while files or media are being accessed. Is there a backup tool or scheduling method that can run only during quiet periods or when the server is otherwise idle? I'd also prefer to keep the backup drive separate so it can be used as a fallback if the main storage drive fails.
2 Answers
Running the two drives as a RAID-1 mirror would keep a copy available if one drive fails, and reads may be spread across both disks. However, RAID is not a backup: accidental deletion, corruption, ransomware, or a problem copied to both drives would affect the mirror. A separate, scheduled backup is safer for recovering older or deleted files.
You could schedule an rsync job with cron during the hours when the server is normally quiet, such as early morning. For example, run it at 3 or 4 AM and use options that preserve metadata while copying only changed files. This won’t detect every possible kind of server activity automatically, but it’s simple and efficient for periodic backups.
That sounds like a good approach. I mainly want to avoid constant disk activity and keep the second drive available as a fallback if the primary one fails.
I’d rather not use RAID because I want the backup disk to remain separate and avoid writing to both drives continuously.