I have a 2 bay NAS, and I was planning on using 2x 18tb HDDs in raid 1. I was planning on purchasing 3 of these drives so when one fails I have the replacement. (I am aware that you should purchase at different times to reduce risk of them all failing at the same time)
Then I setup restic.
It makes backups so easy that I am wondering if I should even bother with raid.
Currently I have ~1TB of backups, and with restics snapshots, it won’t grow to be that big anyways.
Either way, I will be storing the backups in aws S3. So is it still worth it to use raid? (I also will be storing backups at my parents)
RAID is a great backup alternative.
/s
Depends, how much do you value your data? Is it all DVD rips where you still have the DVDs? Nah you don’t really need raid. Are they precious family photos where your only backup copy is S3? Yeah I’d use raid for that, plus having a second copy stored elsewhere.
Plus as others have mentioned there’s checks on your data for bitrot, which absolutely does happen.
RAID does not protect your data, it protects data uptime.
RAID cannot ensure integrity (i.e bitrot protection). Its one and only purpose it to mitigate downtime.
ZFS or other software RAIDs can though. Does anyone stll use hardware raid anyways?
ZFS and BTRFS’ integrity checks are entirely independent of whether you have redundancy or not. You don’t need any sort of RAID to get that; it also works on a single disk.
The only thing that redundancy provides you here is immediate automatic repair if corruption is found. I’ve written about why that isn’t as great as it sounds in another reply already.
Most other software RAID can not and does not protect integrity. It couldn’t; there’s no hashing. Data verification is extremely annoying to implement on the block level and has massive performance gotchas, so you wouldn’t want that even if you could have it.
Yes yes yes yes yes
Raid1 that thing and sleep easier. Good on you for having a cold spare, and knowing to buy your drives at different locations/times to get different batches. Your head is in the right place! No reason to leave that data unprotected if you have the underlying tech and hardware.
RAID is 100% about uptime, not backups. If you want less downtime then RAID is your friend.
Having said that, RAID in modern systems is broken and you should use ZFS instead: https://www.youtube.com/watch?v=l55GfAwa8RI
I always do some level of RAID. If for no other reason, I’m not out of commission if a disk fails. When you’re working with multi TB, restoring from a backup can take a while. If rapid recovery from a disk failure is not a high priority for you, then you could probably do without RAID.
Either way, make sure you test your backups occasionally.
Another way to put it: With RAID, a disk failure is like your Check Engine light coming on. You can still drive, but you should address the problem as soon as you can. Without RAID, it’s like your engine has seized up and you have to tow it for repair and are without your car until it’s fixed.
