How to correctly interpret IOPS?

Question

linux

Hello.
I do not quite understand how to understand the value of IOPS? Yes, these are read-write operations per second, but what is the meaning of this value? After all, you can write to the disk in different blocks, respectively, and the performance will be different.
If you can share, where can I read on this topic? (Yes, a gap in learning)
Thank you all, and sorry for the confusion, the Chukchi is not a writer.

Answer 1

That's right, iops is usually different under different load profiles - different blocks, sequential or random writes, regular or with periodic peaks, parallelism. That's why you can't look at any one number and say the storage device is perfect for the task.

Answer 2

After all, you can write to the disk in different blocks, respectively, and the performance will be different.

On the one hand, yes. On the other hand, technically, the disk interface (and the network, by the way, too) is built in such a way that performance is limited not only by bytes, but also by the number of I / O blocks (or packets for the network).
A large number of small blocks or packets is usually worse.

Answer 3

in IOPS, it is important to compare
the HDD orders, the same one will give as you write - depending on how to score
the same two hdds, they will give better in soft raid
in hard raid with cache - even better (up to limits), without cache - as lucky
by itself , in the raid 0.1 (unused) 5 and 10 (used) are also different
then - ssd, and only ssd in the raid
and then nvme you
take nvme to your computer or laptop - and you even go nuts from the speed of the browser