1. Process Management and System Monitoring
University of Texas Rio Grande Valley Systems Administration CSCI Fall 2016
Instructor Robert C. Jackson
Process Management and System Monitoring

2. Process Management and System Monitoring
University of Texas Rio Grande Valley Systems Administration CSCI Fall 2016
Process Management and System Monitoring
Monitoring and viewing processes and, services
Process – is an instance of a computer executable that is being executed, the actual execution of computer instructions.
Processes are allocated their own set of resourcesimage of executable, virtual memory space, OS data and code segments, security attributes, processor context, and threads.
Process Control Block – is a ‘process data structure’ that keeps track of information regarding processes.
Processes Spawned from other processes are known as child processes, the spawning process is the parent process.
Processes go thru different states of execution1) created when loaded into main memory2) in wait state waiting for scheduler load into a processor3) in blocked state waiting for user input or other resources4) back to wait state after user input or resources acquired5) process terminated upon completion
Process to process communication is accomplished by Inter-Process Communication (IPC) mechanisms.

3. Process Management and System Monitoring
University of Texas Rio Grande Valley Systems Administration CSCI Fall 2016
Process Management and System Monitoring
Monitoring and viewing processes and, services
Process levels – Every Windows and Linux process has a priority assigned to it, the higher the number the higher the priority (Win: 0-30, Linux: 0-15).
Processes are scheduled by a process scheduler that schedules execution and assigns resources based on the processes priority and scheduling policy.
Display process priority levels:
- $ ps –ef | grep some_process
Launch an application with a lower priority:
- $ nice -10 some_app
Lower the priority of a running process:
- $ renice -10 some_running_process
Only root can raise the priority of processes:
- # renice some_runnining_proccess

4. Process Management and System Monitoring
University of Texas Rio Grande Valley Systems Administration CSCI Fall 2016
Process Management and System Monitoring
Monitoring and viewing processes and, services
Windows Process tools:
- taskmgr.exe: Windows Task Manager, view, modify and stop processes.
Windows SysInternals tools:
- handle.exe: displays files and processes that opened them.
- procmon.exe: Process Monitor, shows registry and process/thread activity.
- in a CMD window type: pslist /?  pslist command help
- pslist.exe: lists process information.

5. Process Management and System Monitoring
University of Texas Rio Grande Valley Systems Administration CSCI Fall 2016
Process Management and System Monitoring
Monitoring and viewing processes and, services
Linux Process tools:
/proc virtual filesystem holds files corresponding to Kernel state including hardware information and the currently running processes.
- open a terminal, type: cat /proc/cpuinfo  displays CPU information.
- type: cat /proc/meminfo  displays memory information.
- type: ps aux | less  display all processes a page at a time.
- type: ps –aef | grep more  display detailed process info.
- type: pstree  displays all processes in a hierarchical form.
- type: man pgrep  displays help for the pgrep command.
- type: pgrep –u root sshd  displays process info for sshd as root user.
- type: pkill sshd  stop the ssh daemon process.
- type: kill -9 PID  stop process using Process ID.
- type: pkill –HUP PID  stop process using the SIGHUP (hangup) signal.
- type: top  observe system processes realtime.

6. Process Management and System Monitoring
University of Texas Rio Grande Valley Systems Administration CSCI Fall 2016
Process Management and System Monitoring
Monitoring and viewing processes and, services
Linux Signals:
Signal Value Action Comment
──────────────────────────────────────────────────────────────────────
SIGHUP Term Hangup detected on controlling terminal or death of controlling process
SIGINT Term Interrupt from keyboard
SIGQUIT Core Quit from keyboard
SIGILL Core Illegal Instruction
SIGABRT Core Abort signal from abort(3)
SIGFPE Core Floating point exception
SIGKILL Term Kill signal
SIGSEGV Core Invalid memory reference
SIGPIPE Term Broken pipe: write to pipe with no readers

7. Process Management and System Monitoring
University of Texas Rio Grande Valley Systems Administration CSCI Fall 2016
Process Management and System Monitoring
Monitoring and viewing processes and, services
Service – is an application that usually runs in the background offering core OS features and events. An Operating System (OS) is a set of services which allow for the creation, and execution of application and system programs.
To observe Windows services:
- in a cmd window type: services.msc, observe and scroll the services pane (left).
To observe Linux services:
- in a terminal window type: chkconfig –list | less, observe the services that are listed.

8. Process Management and System Monitoring
University of Texas Rio Grande Valley Systems Administration CSCI Fall 2016
Process Management and System Monitoring
Monitoring and viewing processes and, services
To stop Windows services:
- in a cmd window type: services.msc, observe and scroll the services pane (left). Right Click on a running serviceclick stop
To start Windows services:
in a cmd window type: services.msc, observe and scroll the services pane (left). Right Click on a stopped serviceclick start
To stop Linux services:
- in a terminal window type: chkconfig service_name off, check the service type: chkconfig service_name status, kill running process of service type: service service_name stop.
To start Linux services:
- in a terminal window type: chkconfig service_name on, check the service type: chkconfig service_name status, start process of service type: service service_name start.

9. University of Texas Rio Grande Valley Systems Administration CSCI 6175
University of Texas Rio Grande Valley Systems Administration CSCI Fall 2016
Q&A