What is IO Wait in Linux

This article has everything about how to troubleshoot IO Wait issue in Linux.

The IOWait state, wa when using the top command, indicates the system is waiting on disk or network IO. Because the system is waiting on those resources, it can not fully utilize the CPU.

if we see non-zero values in the wa time column in top command, it serves as a reminder that the I/O subsystem could be a potential bottleneck.