A couple of days back, I started thinking about archiving and backup software. I kind of have backups “sorted”, with my MacBook Pro using BackBlaze to backup to the cloud, Time Machine backing it up to my Synology, my VMs on Proxmox being backed up to Proxmox Backup Server off-site, my Synology and QNAPs being backup to B2 and Hetzner and some other bits and bobs… But for the Archiving stuff, I am not really set up… So, I went looking for archiving software. Couldn’t find anything, so asked on r/DataHoarder. Still no options, at the time of posting, but someone did reply with the idea of using DVDs (or Blu Rays) for ZFS...
Ok, that’s just crazy, but in a kind of a good way… kind of like the floppy RAID stuff I have seen… It does help with the storage of data, plus allows for potential loss of data… but it needs some automation to get it fully perfect…
Assuming you are using this for archiving, you could automate building 5 ISOs, just shy of 100Gb each, once a month, create ZFS ZRAID 2 or 3 (depending on how paranoid you are) and then write your data to it. ZRAID lets you lose 1 disk, giving you around 400GB of usage. Z2 brings that up to 2 losable disks, and 300Gb and Z3 is 3 disks and 200GB. I think Z2 would be your best bet, especially if you are using something like MDisk and are storing them safely.
Once finished, unmount and send an email saying you need to write the ISOs to disk. Label each disk with a unique serial number (this is where the archiving software would be handy) plus the set details and number (so, March 2023 Disk 1/5).
If you need something from that backup you stick it in the drives… You can do it with multiple drives, so with 5 disks and ZRAID, you need to mount a minimum of 4 of them. ZRAID2 needs 3 and ZRAID3 needs a minimum of 2… Ideally, you would want 5 of them, allowing you to check all disks (ZFS Scrub) and then get your files off.
A year of archiving would require 5 drives (say 100 quid a pop, USB makes things easier... Internal is possibly cheaper) and 60 disks (I Found 25 100Gb MDisks disks on Amazon for around 500 EUR) costing a total of maybe 2k, with 15 extra disks…
Follow-up questions:
- Does ZFS allow the mounting of read-only?
- Could you do this with Rewritable BluRay disks? Could they be mounted directly and written to? Leave them in the drives for the month, let writes do their thing and then archive them once a month? It’s archived, so it doesn’t need to be fast…
