> I chose raidz1. With only a handful of disks, the odds of two drives failing simultaneously is fairly low.
Only if you buy different hard drives or at least from different production batches. I had a lot of trouble on the same premise and I won't make that mistake again.
Edit: He mentioned it though ( a bit later in the article)
> The problem is that disks aren’t statistically independent. If one disk fails, its neighbor has a substantially higher risk of dying. This is especially true if the disks are the same model, from the same manufacturing batch, and processed the same workloads. Given this, I did what I could to reduce the risk of concurrent disk failures.
> I chose two different models of disk from two different manufacturers. To reduce the chances of getting disks from the same manufacturing batch, I bought them from different vendors. I can’t say how much this matters, but it didn’t increase costs significantly, so why not?
> I had a lot of trouble on the same premise and I won't make that mistake again.
Please elaborate, I'd love to hear your story!
I hear a lot of advice around raid/z-levels and it often seems backed up by shaky math that doesn't seem to be backed up by reality (like the blog posts that claim that a rebuild of an array of 8 TB drives will absolutely have hard read errors, no exceptions, and yet monthly ZFS scrubs pass with flying colors?)
Only if you buy different hard drives or at least from different production batches. I had a lot of trouble on the same premise and I won't make that mistake again.
Edit: He mentioned it though ( a bit later in the article)
> The problem is that disks aren’t statistically independent. If one disk fails, its neighbor has a substantially higher risk of dying. This is especially true if the disks are the same model, from the same manufacturing batch, and processed the same workloads. Given this, I did what I could to reduce the risk of concurrent disk failures.
> I chose two different models of disk from two different manufacturers. To reduce the chances of getting disks from the same manufacturing batch, I bought them from different vendors. I can’t say how much this matters, but it didn’t increase costs significantly, so why not?