I have a 2 bay NAS, and I was planning on using 2x 18tb HDDs in raid 1. I was planning on purchasing 3 of these drives so when one fails I have the replacement. (I am aware that you should purchase at different times to reduce risk of them all failing at the same time)

Then I setup restic.

It makes backups so easy that I am wondering if I should even bother with raid.

Currently I have ~1TB of backups, and with restics snapshots, it won’t grow to be that big anyways.

Either way, I will be storing the backups in aws S3. So is it still worth it to use raid? (I also will be storing backups at my parents)

  • sugar_in_your_tea@sh.itjust.worksEnglish
    0·
    2 days ago

    I absolutely would, for a few reasons:

    • restoring from backup is a last resort and involves downtime; swapping a disk is comparatively easier and less disruptive
    • it’s possible your backup solution fails, so having some redundancy is always good
    • read performance - not a major factor, but saturating a gigabit link is always nice
    • Atemu@lemmy.mlEnglish
      0·
      2 days ago

      Read perf would be the same or better if you didn’t add redundancy as you’d obviously use RAID0.

      RAID is never in any way something that can replace a backup. If the backup cannot be restored, you didn’t have a backup in the first place. Test your backups.
      If you don’t trust 1 backup, you should make a second backup rather than using RAID.

      The one and only thing RAID has going for it is minimising downtime. For most home use-cases though, the 3rd 9 which this would provide is hardly relevant IMHO.

      • sugar_in_your_tea@sh.itjust.worksEnglish
        0·
        2 days ago

        Read perf would be the same or better if you didn’t add redundancy

        RAID 1 can absolutely be faster than a single disk for read perf, and on Linux it is tuned to be faster. It’s not why you’d use it, but it is a feature of RAID. Intuitively, since both disks have exactly the same data, each disk could read different things. Likewise, for writes, you don’t have to write at the same time, as long as they’re always correct (e.g. don’t flip the metadata segment until both have written the data), so you can even get a write boost.

        If performance is all you care about, then yeah, go ahead and use RAID 0. But you do get a performance boost with mirroring as well.

        Yes, a backup should be tested, but it shouldn’t be relied on. Internet can go down, services can have maintenance, etc, so it’s a lot better to never need it. If you can afford a mirror, it’s having.