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Of course RAID is a backup solution. What is a redundancy if not an immediately available backup? Having a RAID 1 or 5 array ensures that you can continue to se
by Confusion 17y ago
Of course RAID is a backup solution. What is a redundancy if not an immediately available backup? Having a RAID 1 or 5 array ensures that you can continue to serve your data when one of your disks crashes. Saying RAID is not a backup solution is just playing wordgames by redefining 'backup'.
- sp332 17y agoIt's not a backup because if you delete a file from the "main" filesystem, it is immediately deleted from the "backup" as well.
- decode 17y agoI think the important thing here is that the term "backup" only makes sense within the context of what kind of thing you're protecting against. RAID is a useful backup for drive failures, if you're able to replace failed drives within a certain amount of time, but not for manual deletions. DVDs and tapes are useful backups for manual deletions, but not for fires. DVDs and tapes, stored at an offsite location, are useful backups for manual deletions and fires, but possibly not for earthquakes. Since all of the different backup and archival methods have major pros and cons, the only way to say something meaningful about how useful they are is to talk about them within context.
- sjs 17y agoWe've solved this semantic issue. Redundancy is used to refer to availability while backup is used to refer to recovery from data loss. Hence the R in RAID.
- sjs 17y ago"I know this sounds like a semantic quibble, but words mean things." RAID is a redundancy mechanism. It's there in the name. rdiff-backup is a backup tool.
- theBobMcCormick 17y agoRAID is not a backup solution, it's an availability solution. RAID (with the exception or RAID 0 of course) helps you stay available and running in the event of a hardware failure. Raid is no more a "backup" mechanism then load balancing!