TL;DR version: Need a large capacity hard drive (4 TB or more) to use as an offline archive and power back on as needed.
Long version: My mom and dad have important data on their laptops that they wish to get off to their respective desktops, and each of their drives show SMART errors going back at least a year (dad lost a video to corruption as a result, mom shows only speed issues). My plan is to buy a USB 3.0 HDD enclosure and stuff a large capacity, NAS capable hard drive inside of it. From there, once everything is backed up, I would just put the enclosure (w/ the HDD still inside) in a closet until I need it again.
Never used the rescue date service but offering it seems decent to me for something your not gonna touch. If not just any old HDD in large size would work fine for cold storage, but I wouldn't have it be my only back up.
How long to do you plan on keeping these backups and how long are these drives gonna sit unpowered. Anything longer than 5-10 years unpowered then standard HDDs might not be what you want since you cannot guarantee 100% that the data will still be intact.
I would get this drive and look into using btrfs on it. BTRFS will give you a higher chance of the data staying intact.
Yeah but when your file system has a major flaw that should have never existed if you are releasing a quality product, why would you want to trust it for anything. ZFS > BTRFS period.
i run two hitachi 4tb drives for backup as they have the lowest failure rate. however since yours wont actually be running i suppose brand doesn't matter at all. in which case pretty much any drive would suit your need.
I'll also add the obligatory "use solid media as a backup instead" comment
It wouldn't stay powered off for THAT long, my intent is to use it as needed between all the computers in my family, as well as my own. Minimum every 3 months, average every year and a half, 4 years max, all for the sake of throwing numbers out there.
In the mean time, I would be attempting to buy more drives for each computer as time goes on.
I feel like there is something that is specific to long term cold storage, but I don't know. It may be a better idea to have two (or more) disks that you rotate, so that you have a backup of the backup and the data isn't just sitting around potentially turning bad.