I recently got a few (5) hard drives to turn my home server into a NAS with trueNAS scale and my idea is to have 4 usable and 1 for redundancy, my question is… How does RAID work, like what is RAID 0, RAID 5, software RAID etc, and does any of that even matter for my use case?
If you have four drives you can do RAID 6 assuming your controller supports it.
RAID 0 just puts your data on multiple drives, giving you higher read/write speeds but with no built in redundancy.
RAID 1 is just a copy, you have your data duplicated so that if anything fails there’s an immediate copy. No increase in RW speeds.
RAID 5/6 use “parity data” which operates somewhat like RNA/DNA when going through mitosis. The four building blocks TCGA only connect with one of the other four in pairs of two, so even if you have half the data (RNA) you know what the other half is by logical extension. The difference is that 5 uses 3 drives at a time whereas 6 uses 4, you can only withstand the failure of one drive in RAID 5 but 6 can handle the loss of two.
RAID 10 (one-zero, not “ten”) does exactly what the name suggests, it combines the direct copy of RAID 1 with the striping of RAID 0 to give you double RW speeds with redundancy.
Each one will reduce your overall storage by a certain amount, either because of copying the data completely or taking up space for “parity data.” The only one that doesn’t do this is RAID 0 but you have absolutely no redundancy there and if You’re considering RAID for home use I’m going to assume that’s important to you.
I liked the mitosis analogy. May I borrow it?
Might as well, I think it’s how my instructor taught it when I was going through school.
I thought RAID1 enabled faster reads too, because both drives have the complete file. Writes don’t get a speed bump ofc, since those are still bottlenecked by the slowest single drive in the array
That could be, I was trained in systems admin but work as a network engineer by profession. I’ve only set up one server in an enterprise environment and it was using RAID 6.
I’d assume you could read from both disks at the same time though.