From 8f13a880bfe5e417f2937bf338d20810053a0915 Mon Sep 17 00:00:00 2001 From: "Joshua M. Boniface" Date: Wed, 28 Sep 2016 18:54:53 -0400 Subject: [PATCH] Tweaked failures into 4 bullet points as I was repeating myself needlessly --- content/2.md | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/content/2.md b/content/2.md index bdc8841..a956eee 100644 --- a/content/2.md +++ b/content/2.md @@ -11,10 +11,11 @@ RAID protects you against one and only one thing: a disk failure. It does **not* * Multiple disk failures beyond the RAID level chosen (e.g. both disks in a mirror, or 3 disks in a RAID-6). * Failure of the RAID controller itself (especially when using hardware RAID), the computer itself, or the environment (a flood, or fire, perhaps). -* Data corruption on-disk (except for ZFS, and especially for BTRFS) from cosmic rays, or minor hardware or firmware failures. -* File corruption from bad writes or bit rot (except for ZFS), including whole-volume corruption from administrative mistakes (e.g. `mkfs` on an existing filesystem). -* Malicious or accidental deletion or modification of data by yourself or another party, including viruses. +* Data corruption on-disk from filesystem bugs, cosmic rays, or minor hardware or firmware failures. +* Malicious or accidental deletion or modification of files by yourself or another party, including viruses, bad application writes, or administrative mistakes (e.g. `mkfs` on an existing filesystem). The adage is simple: "RAID replicates **everything**, even the stuff you don't want, like the deletion of that file you needed." For these reasons and more, RAID IS NOT A BACKUP! + +ZFS is an interesting case: while it does protect from corruption, it is still susceptable to the other failure modes and hence is still NOT A BACKUP!