Archives for October 2022

The sar command displays system usage reports based on data collected from system activity. These reports consist of various sections, each of which consists of the type of data and the time at which the data was collected. The default mode of the sar command displays CPU usage in various time increments for each category […]

The uptime command displays the time from when a system started running. The output of the uptime command gives information about the current time, how long the system is running, and how many users are currently logged in. Most relevant to CPU troubleshooting, however, is the load average field. A CPU’s load is expressed as […]

The uptime command displays the time from when a system started running. The output of the uptime command gives information about the current time, how long the system is running, and how many users are currently logged in. Most relevant to CPU troubleshooting, however, is the load average field. A CPU’s load is expressed as […]

The killall command sends any specified signal, or the default termination signal, to all processes matching the name specified. Similar to pkill but has a few functional differences, such as matching process names exactly. Here is the syntax: # killall [-u user] [-signal] name… To demonstrate, we will start a couple of instances of the […]

pkill command sends any specified signal, or by default the termination signal, to processes based on a matching pattern. Similar to the pgrep command, but actually sends a signal instead of printing to stdout. For example, if you start top in one terminal, and then issue pkill top in another terminal, you’ll see that top […]

pkill command sends any specified signal, or by default the termination signal, to processes based on a matching pattern. Similar to the pgrep command, but actually sends a signal instead of printing to stdout. For example, if you start top in one terminal, and then issue pkill top in another terminal, you’ll see that top […]

Different commands are used to send signals to processes to terminate or “kill” them. This is necessary when a process becomes unresponsive (hangs), causes system instability, or fails to relinquish control over a file you’re trying to modify. The “kill” command sends any specified signal, or by default the termination signal, to one or more […]

The nohup (“no hangup”) command prevents a process from ending when the user logs off. For example, if an administrator launches a backup script, and then logs off the system, the script would stop running. By placing the nohup command in front of the normal command, the script would continue even after the administrator logged […]

Whereas nice is used to start a new process, the renice command enables you to alter the scheduling priority of an already running process. You use the -n option to specify the new nice value that you want the process to have. When you renice a process group with the -g option, it causes all […]

The nice command enables you to run a command with a different nice value than the default. The -n option increments the nice value by the given integer; if you don’t provide an integer, then the command will assume an increment of 10. By running nice without any options, you’ll see the default nice value. […]