So I have a nearly full 4 TB hard drive in my server that I want to make an offline backup of. However, the only spare hard drives I have are a few 500 GB and 1 TB ones, so the entire contents will not fit all at once, but I do have enough total space for it. I also only have one USB hard drive dock so I can only plug in one hard drive at a time, and in any case I don’t want to do any sort of RAID 0 or striping because the hard drives are old and I don’t want a single one of them failing to make the entire backup unrecoverable.
I could just play digital Tetris and just manually copy over individual directories to each smaller drive until they fill up while mentally keeping track of which directories still need to be copied when I change drives, but I’m hoping for a more automatic and less error prone way. Ideally, I’d want something that can automatically begin copying the entire contents of a given drive or directory to a drive that isn’t big enough to fit everything, automatically round down to the last file that will fit in its entirety (I don’t want to split files between drives), and then wait for me to unplug the first drive and plug in another drive and specify a new mount point before continuing to copy the remaining files, using as many drives as necessary to copy everything.
Does anyone know of something that can accomplish all of this on a Linux system?
Don’t become so concerned with if you could, that you overlook if you should.
I would buy a larger drive.
That would probably be the most elegant solution overall and I appreciate the suggestion, but a new drive costs money that I don’t currently have an abundance of and I already have empty drives that aren’t being used, which I had accumulated over time and had already paid for ages ago. If I’m being honest, the reason I want to do it this way is because I don’t really see the value of using a brand new drive for an offline backup of personal data where the drive will be plugged in at best once a month before being stored in a drawer. If I buy a brand new drive I’d rather actually use it as part of the active storage in my server and keep it running to get the most utility out of it.
https://www.gnu.org/software/tar/manual/html_section/Using-Multiple-Tapes.html
Might do kind of what you want.
Something like mergerfs? I think this is what Unraid uses if I remember right.
If OP cant use more than one disk at once, how can they benefit from mergerfs?
https://www.gnu.org/software/tar/manual/html_node/Multi_002dVolume-Archives.html
You might end up splitting files across drives, but I don’t think you’re likely to find a more “out of the box” solution. You might combine it with the compression flags to make sure things fit, and don’t forget to number your drives!
Git annex can do that and keep track of which drive the files are on.
