RAID or single drive for backups?

cron , 3 months ago

I would recommend avoiding RAID for backups. It's preferable to have two separate backup disks in two distinct systems rather than relying on mirrored backup disks. If there's a human error on the backup machine, you risk losing both backups simultaneously. Additionally, unforeseen events like system failure due to a lightning strike could compromise your data. Ideally, you should have two backups stored in two different location.

kylian0087 , 3 months ago

Any storage shut be raid or a form their of in a ideal world. The storage where backups are stored a defiantly yes raid shut be a very high priority.

BearOfaTime , 3 months ago

I haven't needed RAID for years, because my storage needs were small enough to fit on currently available drives.

Which is why my file server has a single 4TB data drive, with an external attached for mirroring on a schedule, plus a NAS also mirrored on a schedule, and Crashplan.

The NAS was recently added, and it's RAID 5, only because it was free and I had the drives sitting around collecting dust. Hopefully I can switch it to RAID 6 once deduplication is finished.

Technically only Crashplan is a real backup in my setup. The rest is just local redundancy.

I'd prefer to not use RAID if I can avoid it.

kylian0087 , 3 months ago

Raid is not only for if a drive fails. But can also be used against slow corruption of files. If you love your data use raid.

Atemu , 3 months ago

That is just a specific type of drive failure and only certain software RAID solutions are able to even detect corruption through the use of checksums. Typical "dumb" RAID will happily pass on corrupted data returned by the drives.

RAID only serves to prevent downtime due to drive failure. If your system has very high uptime requirements and a drive just dropping out must not affect the availability of your system, that's where you use RAID.

If you want to preserve data however, there are much greater hazards than drive failure: Ransomware, user error, machine failure (PSU blows up), facility failure (basement flooded) are all similarly likely. RAID protects against exactly none of those.

Proper backups do provide at least decent mitigation against most of these hazards in addition to failure of any one drive.

If love your data, you make backups of it.

With a handful of modern drives (<~10) and a restore time of 1 week, you can expect storage uptime of >99.68%. If you don't need more than that, you don't need RAID. I'd also argue that if you do indeed need more than that, you probably also need higher uptime in other components than the drives through redundant computers at which point the benefit of RAID in any one of those redundant computers diminishes.

slazer2au , 3 months ago

I would go with raid on the backup system too. you don't want all your backups disappearing because one drive fails.

BCsven , 3 months ago

Depends on them not choosing wrong raid type :)

slazer2au , 3 months ago

That is why I say "RAID0 is not RAID."

BCsven , 3 months ago

Where? not in what i replied to