ionice:tldr:ba374
The ionice command is used to control the disk I/O (Input/Output) priority for a specific process on Linux systems. The -p option is used to specify the process ID (pid) of the process for which the disk I/O priority needs to be managed. ${pid} in this case is a placeholder for the actual process ID.
The disk I/O priority determines the amount of access a process has to the storage devices, such as hard disks, in terms of read and write operations. The ionice command helps in prioritizing or limiting the disk I/O usage of a specific process. By default, all processes have the same priority level, but using ionice allows you to adjust this priority.
For example, if you want to set the disk I/O priority of a process with process ID 1234, you would use the command: ionice -p 1234.
Depending on the system configuration, this command may require administrative privileges, so it might need to be executed with sudo or as the root user.