Which RAID level to choose to store many large files?

Question

RAID

It is necessary to store a lot of multimedia files with which you are constantly working on a file cleaner. It seems that RAID-5 is suitable, but I read that it is very problematic to rebuild for large volumes. It's true? If so, which RAID level should I choose? Files approximately 8TB

Answer 1

There are three main raids 0, 1, 5
0 - STRIPE physical disks are combined into one large logical disk. Access speed is the highest. The risk is also the highest (one disk fails - the entire logical disk fails).
1 - MIRROR two physical disks are merged into a mirror. Reading speed can increase, write speed - as with a single disk. If one drive fails, the logical drive continues to operate as if nothing had happened. That is, the risks are reduced, but the cost is doubled.
5 - RAID-5. A minimum of 3 disks is required. The disks are combined into one large logical one, but one of the disks stores "correction code". To speed up the work, the correction block can be interleaved on different disks. Read and write speed is improved. The risk - also decreases - if any one disk fails, the logical disk continues to work (but slowly, and it is necessary to quickly replace the failed disk). Fast operation requires the correction code to be computed quickly, so RAID5 is rarely software-based, more often a separate device with a separate processor.
The cost of RAID5 is much cheaper than mirror, especially as the number of disks increases. With three disks - you overpay 33%, and with five disks - 20%, and with 10 disks - 10%.
The rest is a combination of the above raids.
Thus, you need to independently understand what tasks you assign to the raid.
Speed ​​up? increasing resiliency? Just combining disks for the sake of volume?
Or maybe you don't need a raid at all, but just buy a few screws and store many large files in different folders?

Answer 2

The question is different. Do you need speed or fault tolerance? Or all together?
1. For speed - raid 0.
2. For fault tolerance - raid 1.
3. To combine both options, you can raid 5, but better than 10 (aka 1 + 0 or 0 + 1 - essentially the same, depends on how do, but the result is basically the same).
For 0 and 1 raids, two disks are enough. For 5 - at least 3, and for 10 - at least 4. At the same time, in 5, the size of the raid will be the sum of 2 of 3 disks, and raid 10 will also have the sum of two of the four disks. A copy of the data will be written to the other two.
Choose.