Process management

Process management

1. top

   • Process activity continuously
   • Better than GUI
   • Options
     • -b batch mode
     • -n num iterations
     • -q no delay
       • only SU
     • -s secure mode
   • Single key commands
     • h help
     • k kill
     • n change priority
     • q quit program
     • r report
     • s delay
   • System summary
     • Program name
     • Date
     • uptime
     • users
     • tasks
     • CPU Activity
       • user
       • system
       • nice
       • idle
       • waiting
     • Memory
       • used
       • free
       • buffer
     • swap
       • used
       • free
       • catched
     • Load average
       • 60 seconds
       • 5 minutes
       • 15 minutes
   • CPU activity processes
     • PID
     • user
     • PRI
     • NI
     • %CPU
     • %Memory
     • TIME
     • command

2. PRIORITIES

   • Priorize processes execution
   • kernel handles automatically
   • PR column
     • relative
     • top
     • ps -l
     • +PR +time CPU
   • nice command
     • +nice -priority
     • -nice +priority
     • before start
     • assign priority
       • users 1 to 19
         • default 0
       • SU -20 to 19
         • default 10

3. RUN LEVELS

   • preset state
   • boot
   • init
   • Single digit integer
     • 0 halt
     • 1 single user
     • 2 Multiple user, no NFS
     • 3 Multiple users command line
     • 4 User-definable
     • 5 Multiple user GUI
     • 6 Reboot
     • default
       • 3
       • 5
     • defined
       • 2
       • 4
   • solve problems
   • /sbin/runlevel
   • default
     • /etc/inittab
   • cat or telinit