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ionice
Ionice is a command-line tool that allows users to prioritize disk I/O for a given process or command under Linux. It works by manipulating the ionice values associated with processes, which determines their I/O priority.
The tool provides three different I/O classes that can be assigned to processes: idle, best-effort, and real-time. The idle class provides the lowest priority to the process, allowing it to use disk resources only when no other process is requesting them. The best-effort class is the default and provides a balanced allocation of disk I/O resources to processes. The real-time class gives the highest priority to the process, allowing it to access disk I/O resources with higher preference.
Each class, except idle, has eight different priority levels ranging from 0 to 7, with 0 being the highest and 7 the lowest. The higher the priority level, the more access the process will have to the disk I/O resources.
Ionice is usually used with the 'ionice' command followed by the priority level and command to be executed. For example, 'ionice -c2 -n0' sets the process to the highest best-effort priority level.
Using ionice can be particularly useful when running demanding tasks in the background without affecting the responsiveness of the system, as it allows users to allocate disk I/O resources more efficiently. This is particularly important in scenarios where multiple processes are competing for disk access.
Ionice is part of the util-linux package and is available by default on most Linux distributions. It is a powerful tool that can optimize disk I/O operations and improve system performance by fine-tuning process priorities.
List of commands for ionice:
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ionice:tldr:3fa12 ionice: Set I/O scheduling class of a running process.$ ionice -c ${scheduling_class} -p ${pid}try on your machineexplain this command
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ionice:tldr:afdf5 ionice: Run a command with custom I/O scheduling class and priority.$ ionice -c ${scheduling_class} -n ${priority} ${command}try on your machineexplain this command
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ionice:tldr:ba374 ionice: Print the I/O scheduling class and priority of a running process.$ ionice -p ${pid}try on your machineexplain this command