Process Management

fuser :-The fuser command lists the process identifiers (PIDs) of those processes that have one or more specified files or file structures open There are subtle differences in the command output..

iostat :-The iostat command reports the following Input/Output statistics:

• the number of characters read and written per second for terminals (collectively)

• the number of transfers per second for each disk

• the number of kilobytes transferred per second for each disk

• the percentage of time the system spent

— in user mode,

— in user mode running low priority (nice) processes,

— in system mode, and

— idling.

Nice:- The nice command lets you run a specified command at a lower (time-share) priority. The C Shell has a built-in version of this command.

kill :-The kill command sends a signal to one or more running processes; the default is to send the SIGTERM signal (signal number 15), which usually terminates processes that do not ignore or catch the signal. The HP-UX version of this command was updated so that -s precedes the signal name or signal number.

killall :-The killall command sends a KILL signal to all processes started by the user, except the calling process. The default is to terminate those processes. When started by the superuser, the killall command kills all processes that can be terminated, except those processes that started it, the kernel processes, and processes 0 and 1 (init).This command also may be used to send another, specified signal to the processes.

ps :-This command displays the current statistics for running processes, and reports CPU usage, the processor and processor set, and the scheduling priority. This command provides a snapshot of the system at the time the ps command is executed. Common use of the ps command is ps -elf on HP-UX

renice:- This command alters the scheduling priority of one or more running processes.

sar :-The sar command reports the following:

• cumulative system activity, including CPU utilization,

• buffer activity,

• the transfer of data to and from devices,

• terminal activity,

• the number of specific system calls used,

• the amount of swapping and switching activity,

• the amount of switching activity,

• queue lengths,

top :-The top command provides continuous reports on the state of the system, including a list of the processes using the most CPU resources. The top command samples the system and continually updates its display; by contrast,

vmstat :-This commands displays information about process threads, virtual memory usage (page lists, page faults, page ins, and page outs), interrupts, and CPU usage (percentages of user, system, and idle times). First reported are the statistics since boot time; subsequent reports are the statistics since a specified interval of time.