Scheduled Process Control Chap' 10

1
Scheduled Process Control(Chap. 10)

• ICE System Consultant 2nd
• 2002? 7? 24?

2
Objectives

• Start the CDE Process Manager to monitor and
  control active processes
• Report active process statistics using the prstat
  command
• Schedule the automatic execution of commands,
  programs, or scripts using the commands at and
  crontab
• Define the files used to control user access to
  the commands at and crontab
• Create and execute an at job
• Describe the location and format of a crontab
  file
• Demonstrate the steps to create, view, edit, and
  remove a crontab

3
Processes Running on The System

• All processes are assigned a unique process
  identification number (PID)
• The method that shows the process state
• ps command
• For viewing a list of processes currently running
  on a system
• The CDE Process Manager
• The prstat command
• Solaris 8 Operating Environment only
• top command
• Download from http//sunfreeware.com/

4
CDE Process Manager

• Tool Menu
• The red box
• /usr/dt/bin/sdtprocess command can execute the
  Process Manager

5
CDE Process Manager (Cont.)

• The Process Manager can sort processes for
  selected column
• To terminate a process, highlight it, and then
  either press Control-c or select Kill from the
  Process menu

6
The prstat Command

• Solaris 8 only
• prstat
• PID
• Username
• Size
• The total virtual memory size of the process
  (memory swap)
• RSS
• The resident set size of the process
• State
• Pri
• Nice
• The value used in priority computation
• Time
• Cpu
• Process/nlwp
• The name of the process
• The number of lightweight processes (LWPs) in the
  process

LWP is a virtual CPU or execution resource
7
The prstat Command (Cont.)

• Options

8
Scheduling The Automatic Execution of Commands

• The crontab command
• crontab
• Automatically execute commands or scripts
  repetitively
• /var/spool/cron/crontabs/username
• Maintain all crontab files
• The user can view, edit, or remove a crontab file
• Crontab file format
• minute hour day month week command-line (Sunday
  0, in week)
• 10 /usr/bin/audioplay /usr/demo/SOUND/soun
  ds/ring.au
• ?? 10?
• View a crontab file
• crontab l

9
Scheduling The Automatic Execution of Commands
(Cont.)

• Edit a crontab file
• Need to global variable EDITOR (vi)
• crontab e
• Controlling crontab access (for root)
• /etc/cron.d/cron.allow
• /etc/cron.d/cron.deny
• If neither of them are exist, root can only use
  the crontab
• Delete a crontab file
• Crontab r
• crontab Control D

10
Scheduling The Automatic Execution of Commands
(Cont.)

• The at command
• Used to automatically execute a job at a
  specified time just one
• at 230 pm
• atgt/usr/bin/audioplay /usr/demo/SOUND/sounds/ring.
  au
• View the schedule
• atq
• /var/spool/cron/atjobs/files
• Delete the schedule
• at r job id
• Controlling the at access
• /etc/cron.d/at.allow
• /etc/cron.d/at.deny
• If neither of them are exist, root can only use
  the at command