Tuesday, 30 April 2013

What does the status D,R,S,Z indicate when i run top /ps aux command?

       D   uninterruptible sleep (usually IO)
       R   runnable (on run queue)
       S   sleeping
       T   traced or stopped
       Z   a defunct ("zombie") process

       For BSD formats and when the "stat" keyword is used, additional letters may be displayed:
       W   has no resident pages
       <   high-priority process
       N   low-priority task
       L   has pages locked into memory (for real-time and custom IO)

Linux process state codes

Here are the different values that the s, stat and state output specifiers
(header "STAT" or "S") will display to describe the state of a process.

D Uninterruptible sleep (usually IO)

R Running or runnable (on run queue)

S Interruptible sleep (waiting for an event to complete)

T Stopped, either by a job control signal or because it is being traced.

W paging (not valid since the 2.6.xx kernel)

X dead (should never be seen)

Z Defunct ("zombie") process, terminated but not reaped by its parent.

For BSD formats and when the stat keyword is used, additional characters may be displayed:

< high-priority (not nice to other users)

N low-priority (nice to other users)

L has pages locked into memory (for real-time and custom IO)

s is a session leader

l is multi-threaded (using CLONE_THREAD, like NPTL pthreads do) 

+ is in the foreground process group


  1. Thanks Shankar, You are really doing a great job. I like your tutorial on how to STAT of Predefined Linux Words.

  2. Really nice thing you had posted here. And i hope this strategies will help the people for hiring process. Thank you and also i am expecting much more post from you. So please keep update like this.

    Hr Consultancy in Chennai