On 17 Jan 2024 20:23 -0500, from hunguponcont...@gmail.com (Default User): > BTW, the two backup drives are external 4 Gb USB HDDs. The secondary > backup drive is always kept away from the computer, in a locked steel > box, except when it is attached to the computer to have the primary > backup drive copied to it. > > The primary backup drive is almost always attached to the computer, so > that I can access files archived there, that are not on the computer. > Probably not good practice, but that's why I have the secondary backup > drive.
Hold on. Let's pause right here. **That "primary backup drive" is not a backup at all.** If at any point it can legitimately contain the only copy of a file that you want to keep, then conceptually it is not a backup. If it is continuously accessible from the system that you're trying to protect, then anything bad which happens to that system is liable to also at least potentially affect your "primary backup drive" as well. There is nothing wrong with using external storage media to expand the storage capacity of your computer, but you really shouldn't treat or consider it as being a backup, because a backup is a _second_ copy to be used if the primary copy somehow becomes unusable, corrupt, inaccessible or whatever else might be the case. Solve the right problem. > I guess in the back of my mind I was thinking of a scenario where a > file on the primary backup drive might be corrupted or deleted before > being copied to the secondary backup drive. Then if it is not present > on the primary backup drive, rsync dutifully deletes it from the > secondary backup drive. If the file is no longer on the computer's > internal SSD, I am then SOL. That is why a backup scheme should include some form of retention; ideally immutable. A single botched backup run should not risk the integrity of an only backup. > BTW(2), I do use rsnapshot with cron jobs to back up the internal SSD > to the primary backup drive daily (and weekly, monthly, yearly). But I > am not sure if I could also use it to do copies of the primary backup > drive to the secondary backup drive (maybe using an additional > configuration file)? You can use rsnapshot with any number of different configuration files. Just pass `-c` to it to name the configuration file other than the default. (For a long time I had two, and a script selecting either one based on the backup target drive in use for that particular backup. Worked great.) > As for ZFS . . . I wish! But I think the resource requirements would > be too high for my setup, so it probably would be impractical - or > impossible. And then there's the complexity. And the learning curve. ZFS works fine on low-spec'd systems. I use it on a VPS with 2 GB RAM without any problems. You really want 64-bit, but that's about it. And while ZFS _can_ be complex, and supports rather complex usage scenarios (because it is, at its core, an enterprise solution), at the basic level the biggest difference is that you write "zpool create" instead of "mkfs.ext4". -- Michael Kjörling 🔗 https://michael.kjorling.se “Remember when, on the Internet, nobody cared that you were a dog?”
