Sorry, lazy to learn how to use iometer, but you probably have SSD too and can report your results.
Okay, not a problem: https://imgur.com/a/teoPGrz
Real world performance[+Mix], Read&Write[+Mix]
One is Fujitsu DX200 S4 SSD SAN, other is HFM256GDJTNG-8310A.
Can you guess which is where?
>> but you probably have SSD too and can report your results.
Uh-uh!
I intended to show you the difference between a single NVMe drive and a SSD SAN (a bit old, but still very performant to handle ~900 VMs).
Sure, I can just ramp up queue depth and see some magical numbers, but for me the real performance is in everyday tasks and running CrystalMark isn't an everyday occurrence.
Did you guess which one is SAN?
I am bit confused how random 4k access is relevant to your task, it should be more like 1MB seq access likely.
My everyday task is tuning heavy data processing pipeline, and I am trying hard to achieve those q16t16.
Sorry? 900 VMs equals 100% full random access. There is no sequential access there, just as I said in my first comment.
> It is obvious there is a difference
Because of your comment[0].
This comment[1] pretty much summarized what I said in a more eloquent way.
it depends on workload, if they do most of the work in RAM, and most of fs traffic is snapshoting and restoring from snapshots, then you will get 99% io seq traffic. If they do some non-trivial fs operations, then you will get q16t16 io traffic. It is very unlikely you will get q1t1 random.
> Because of your comment[0]. > This comment[1] pretty much summarized what I said in a more eloquent way.
In my view you are jumping from topic (single ssd vs nas) to another topic (your speculations about benchmark not representing real world scenarios) and then back.
Also 1GB test file is often fits in the SSD's RAM cache. Get iometer, 50R/50W%, blocks from 512 to 16k, at least half the size of the storage. Then you would see the real performance.
NB if you have random read way below the random write means you are measuring anything but the storage performance.