Quoting Joel W. Shea via luv-main (luv-main@luv.asn.au):
I'd like to add that a mirror isn't a reliable backup; regardless of that mirror being RAID, or scheduled synchronisation.
I'll quote my own bit from 2002: The topic of data backup herewith returns, like a troublesome data set — occasioned by my addressing the matter on a mailing list, and again referring people to your [my friend Karsten Self's] Linux Backups mini-FAQ. Comments will concern that FAQ and surrounding cosmic truths. Cosmic truth #1: Part of the reason it's a FAQ topic is that people are confused about what a backup is, and what it is not. o redundant storage: E.g., RAID1, RAID5. o archival storage: E.g., migrating a billed-out project's files from the company file server to CDRs. o backup: Technical means to make your data survive Thor hitting your server with Mjolnir. Or to get back the directory Moriarty deleted from it last Thursday. These are _very_ distinct concepts, yet many people have them hopelessly confused, and call all of them "backup". A lot of the people with dumb opinions on the subject have no friggin' clue what it takes to foil Thor and Moriarty: They think quantity one duplicate copy, stored within Mjolnir distance of the server, and overwritten every Saturday night with a fresh data set, is "backup". 'Backup Fallacies / Pitfalls' on http://linuxmafia.com/faq/Admin/ -- Cheers, (morganj): 0 is false and 1 is true, correct? Rick Moen (alec_eso): 1, morganj rick@linuxmafia.com (morganj): bastard. McQ! (4x80) -- seen on IRC