What is IO Delay?

Question

Monitoring

Proxmox has some statistics on the server, under IO wait there is IO Delay .
What does this mean ? What does it have to do with hdd?

Answer 1

Input Output
This is the rate at which information is being input or output. Accordingly, wait - waiting for the processor to read / write information to a disk or other devices, delay - delay.
The amount of CPU idle (idle) waiting for information from disks.
Here you can read something.