Data being accessed from our Docker containers will mostly reside in physical storage devices, such as hard disks or solid state drives. Underneath Docker's copy-on-write filesystems is a physical device that is randomly accessed. These drives are grouped together as block devices. Data here is randomly accessed fixed-size data called blocks.
So, in case our Docker containers have peculiar I/O behavior and performance issues, we can trace and troubleshoot what is happening inside our block devices using a tool called blktrace. All events that the kernel generates to interact with the block devices from processes are intercepted by this program. In this section, we will set up our Docker host to observe the block device ...
