Hardware Question about raid hard drive enclosures

[PalomPorom]

So I have a lot of data. I'm talking 16 8TB hard drives. And Im shopping for a new enclosure. I understand the whole raid0 thing for 2 drives so I constantly have a backup. But in larger enclosures like an 8 bay would I be able to set it to raid0 for just 2 of the drives?
Like instead of having 8 seperate 2 bay enclosures set to raid 0, I get a 8 bay one and have 4 seperate pairs of drives running raid0? Or is that not how it works?

Also what is hot swapping? Couldn't find an answer with Google. And sorry if I'm a noob and don't make any sense. I've been up for a couple days so give me some slack lol

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[KleinesSinchen]

RAID is not a backup! RAID does not replace a backup!

It is used to improve speed and/or availability/reliability of data storage.
If you use a hardware RAID controller and the controller dies, all data can be permanently lost – depending on the documentation and/or availability of replacement controllers.

There are different RAID levels. The easiest are RAID 0 and 1
RAID 0 – stripe. Two (or more) drives act as one→

• Improves performance (mostly for big files).
• Less secure. One drive fails →RAID array gone.
• 100% of the storage space available

RAID 1 – mirror. Two (or even more) identical copies are written (and deleted!) simultaneously→

• Resistant against a failing drive;
• no performance gain.
• 50% of the storage space available

RAID 1+0: At least 4 drives. Two RAID 0 Arrays are mirrored.→

• Resistant against a failing drive (in the best case more)
  
• Improves performance
• 50% of the storage space available

RAID 5: – block striping with distributed parity; minimum 3 drives→

• Resistant against a failing drive
• Improves performance
• If you have n drives, the storage of n-1 drives is available

RAID 6: – like 5 but with double parity; minimum 4 drives→

• Resistant against two failing drives
• If you have n drives, the storage of n-2 drives is available.

Read more on en.wikipedia.org

Edit:
Hot swapping: Your data storage enclosure allows pulling out a (failed) HDD/SSD while the machine keeps continuing normal operation. Once a new drive is inserted it starts rebuilding redundancy.

 

[PalomPorom]

My bad I got 0 and 1 mixed up. I meant raid 1 the whole time

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[FAST6191]

RAID 1/mirrored drives is still not a backup -- electrical surge, fire, flood, thief... data still just as gone. All it means is if one dies then you hopefully notice in time and copy the data off (if you have two drives, probably same batch, same amount of writes, same on time, same cooling history, same number of times dropped... they tend to follow the other into the grave).


"But in larger enclosures"
Depends upon the controller and setup. For a PC based thing ( https://freenas.org/ ) then trivial -- you might have to set it in the BIOS or the RAID card boot menu but still nothing drastic. Beyond that and going into embedded world you need to look at the specific models. By the time you are getting 8 bay things then it is usually an expected feature but start going into the cheaper low end NAS and you might not. You can also twist it a bit and do multi level RAID (usually written with a + in the numbers) -- 0+1 takes 4 drives but combines 2 in a RAID0 and then mirrors that theoretically giving the best of both worlds in terms of speed and reliability.
I should also note some of the two drive portable hard drive things you have to turn such things on for. They were popular with photographers at one point and many did not turn it on.

 

[Originality]

Storage Pools are also a thing, but I tend to only see them in enterprise solutions. It lets you dynamically assign volumes as high availability (read, RAID 1), high performance (RAID 0) or just normal storage (JBOD), as well as dynamically add or remove drives to the storage pool as required (marking any removable drives as temporary, just like hot-swapping).

There are also solutions that periodically back up data from the array to the cloud, so you may want to keep an eye out for those if you want true redundancy of your data (or parts of it).

 

[PalomPorom]

Storage Pools are also a thing, but I tend to only see them in enterprise solutions. It lets you dynamically assign volumes as high availability (read, RAID 1), high performance (RAID 0) or just normal storage (JBOD), as well as dynamically add or remove drives to the storage pool as required (marking any removable drives as temporary, just like hot-swapping).

There are also solutions that periodically back up data from the array to the cloud, so you may want to keep an eye out for those if you want true redundancy of your data (or parts of it).

I thought about subscribing to cloud services but with the amount of data that I have idk. I'll be uploading for a year. Plus I think all services that I know of have a data cap. That and I kinda don't want this data on the net. Lots of piracy lol

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