What actually counts as a copy under the 3-2-1 rule, why a RAID mirror or a snapshot only protects against one kind of failure, and the one-page inventory that exposes the gaps.

  • wr2623@midwest.social
    link
    fedilink
    English
    arrow-up
    1
    ·
    2 days ago

    I hate this take, and it seems to contradict itself.

    What actually counts A copy counts when it survives the loss of the thing it was copied from. That one sentence settles most arguments about what is and isn’t a backup.

    So doesn’t raid count then? If a drive fails and the second drive survives the loss, it is a backup…

    Just because the copy is synchronous doesn’t mean it isn’t a backup, it just means it protects from a different type of failure.

    • RAID: protects against a drive failure
    • Snapshot: protects against user failure (rm *)
    • Replication: protects against admin failure (zpool destroy)
    • Offsite tape/async backup: protects against replication corruption, and total site failure

    These are all backups, just with different recovery point objectives/recovery time objectives, and all just as important.

  • Avid Amoeba@lemmy.ca
    link
    fedilink
    English
    arrow-up
    3
    ·
    4 days ago

    Sloppy, somawhat difficult to read. Should use a model that’s better at writing English. 😄