Transcript ppt4 - UTRGV Faculty Web - University of Texas Rio Grande Valley

University of Texas Rio Grande Valley Systems
Administration
CSCI 6175.01 Fall 2016
Instructor Robert C. Jackson
Process Management and System Monitoring
University of Texas Rio Grande Valley Systems
Administration
CSCI 6175.01 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.
University of Texas Rio Grande Valley Systems
Administration
CSCI 6175.01 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 - -10 some_runnining_proccess
University of Texas Rio Grande Valley Systems
Administration
CSCI 6175.01 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.
University of Texas Rio Grande Valley Systems
Administration
CSCI 6175.01 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.
University of Texas Rio Grande Valley Systems
Administration
CSCI 6175.01 Fall 2016
Process Management and System Monitoring
Monitoring and viewing processes and, services
• Linux Signals:
Signal
Value
Action
Comment
──────────────────────────────────────────────────────────────────────-----------------------------SIGHUP
1
Term
Hangup detected on controlling terminal or death of
controlling process
SIGINT
2
Term
Interrupt from keyboard
SIGQUIT
3
Core
Quit from keyboard
SIGILL
4
Core
Illegal Instruction
SIGABRT
6
Core
Abort signal from abort(3)
SIGFPE
8
Core
Floating point exception
SIGKILL
9
Term
Kill signal
SIGSEGV
11
Core
Invalid memory reference
SIGPIPE
13
Term
Broken pipe: write to pipe with no readers
University of Texas Rio Grande Valley Systems
Administration
CSCI 6175.01 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.
University of Texas Rio Grande Valley Systems
Administration
CSCI 6175.01 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.
University of Texas Rio Grande Valley Systems
Administration
CSCI 6175.01 Fall 2016
Q&A