How to Understand Linux Process Statuses

In our “How to use ps” article we talked about the Linux command ps and how it can be used to examine the currently running processes on a Linux server.

When using ps with the “u” flag (ps -u) you will see a column called STAT that displays the process’s status.

Here is a list of the various process statuses and what they mean:

D – Uninterruptible sleep (usually a critical system process, a process that cannot be killed without rebooting)
R – Running or runable (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.
Z – Defunct (“zombie”) process, terminated but not closed by the parent process that created it

Additional characters may be seen if in a BSD environment or when using the “stat” modifier with ps:

W – has no resident pages
< – high-priority process
N – low-priority task
L – has pages locked into memory (for real-time and custom IO)

===

Liquid Web’s Heroic Support is always available to assist customers with this or any other issue. If you need our assistance please contact us:
Toll Free 1.800.580.4985
International 517.322.0434
support@liquidweb.com
https://my.liquidweb.com/