Processes in D state - Revision history

12.200.60.7: grep D was to broad of a query, you only care about field 10 containing D

2012-08-29T19:00:14Z

grep D was to broad of a query, you only care about field 10 containing D

Custa: /* See also */

2012-05-11T01:38:58Z

‎See also

Kir: Reverted edits by Waexu66 (Talk) to last revision by Rogerdpack

2010-07-30T15:00:10Z

Reverted edits by Waexu66 (Talk) to last revision by Rogerdpack

Waexu66 at 14:09, 30 July 2010

2010-07-30T14:09:13Z

Rogerdpack: add a link to know what the '+' means

2009-02-11T19:35:44Z

add a link to know what the '+' means

Openhacker at 22:40, 30 January 2007

2007-01-30T22:40:30Z

Kir: Minor spelling fixes, some rewording and reformatting

2006-06-12T21:10:44Z

Minor spelling fixes, some rewording and reformatting

Vass: Initial edition of article

2006-06-11T13:45:27Z

Initial edition of article

New page

If there are a lot of processes in D state in your system, then something is wrong with it.
What is "D state" and process state in generally? A process in Linux can be in several states: runing state,
sleeping state and others. Running process runs on a CPU just now, Sleeping process waits for its turn on CPU
or for some other event. Using ps command you can obtain information about state of each process in the system: STAT column shows that:
<pre>
[root@dhcp0-56 ovz-utils]# ps a
PID TTY STAT TIME COMMAND
4975 tty1 Ss+ 0:00 /sbin/mingetty tty1
4976 tty2 Ss+ 0:00 /sbin/mingetty tty2
6202 pts/0 Ss+ 0:01 -bash
10312 pts/1 Ss 0:00 -bash
639 pts/1 R+ 0:00 ps a
</pre>

First big '''S''' stands for Sleeping, '''R''' stands for runing
("+" means that the process is foreground and small "s" means that the process is session leader, but it isn't relevant in our discussion).
D state occurs then the process is in uninterruptable disk sleep. This state is bad, because you can't do anything with the process in D state.
Fortunately, process normally remains in such state not for long.
If you have a heap of D state processes than some logic in system is disrupt. The very important thing then is to determine,
where this unlucky sleep occurs. It is easy to do with ps command with ''l'' option. WCHAN column shows the name of the kernel function where
the process is sleeping:

<pre>
[root@dhcp0-56 ~]# ps axl | grep D
F UID PID PPID PRI NI VSZ RSS WCHAN STAT TTY TIME COMMAND
vass 13478 7.2 0.0 1732 624 pts/1 D+ 17:36 0:00 find ./
</pre>

Then you have problem with D state processes always attach this information to the report, that you send to developers.

[[Category: Troubleshooting]]

← Older revision		Revision as of 01:38, 11 May 2012
Line 29:		Line 29:
	[http://wiki.preshweb.co.uk/doku.php?id=linux:psflags] describes the various states.		[http://wiki.preshweb.co.uk/doku.php?id=linux:psflags] describes the various states.
	[[Category: Troubleshooting]]		[[Category: Troubleshooting]]
		+
		+	Process waiting for its turn on CPU is in R state.

← Older revision		Revision as of 15:00, 30 July 2010
Line 29:		Line 29:
	[http://wiki.preshweb.co.uk/doku.php?id=linux:psflags] describes the various states.		[http://wiki.preshweb.co.uk/doku.php?id=linux:psflags] describes the various states.
	[[Category: Troubleshooting]]		[[Category: Troubleshooting]]
−
−	~~[http://www.resumesplanet.com resume help]~~

← Older revision		Revision as of 14:09, 30 July 2010
Line 29:		Line 29:
	[http://wiki.preshweb.co.uk/doku.php?id=linux:psflags] describes the various states.		[http://wiki.preshweb.co.uk/doku.php?id=linux:psflags] describes the various states.
	[[Category: Troubleshooting]]		[[Category: Troubleshooting]]
		+
		+	[http://www.resumesplanet.com resume help]

← Older revision		Revision as of 19:35, 11 February 2009
Line 26:		Line 26:
	{{Note\|In case you have problem with the D state processes, always attach this information to the report you send to developers.}}		{{Note\|In case you have problem with the D state processes, always attach this information to the report you send to developers.}}

		+	==See also==
		+	[http://wiki.preshweb.co.uk/doku.php?id=linux:psflags] describes the various states.
	[[Category: Troubleshooting]]		[[Category: Troubleshooting]]

@@ Line 16: / Line 16: @@
 First big '''S''' stands for Sleeping, '''R''' stands for running ("+" means that the process is foreground and small "s" means that the process is session leader, but it is not relevant for this article).
-'''D''' state occurs then the process is in uninterruptible disk sleep. This state is bad, because you can't do anything with the process in D state. Fortunately, process normally remains in such state not for so long. But if you have a heap of D state processes then some logic in system is disrupt. If that is happening, the very important thing is to determine where this unlucky sleep occurs. It is easy to do with ps command with ''l'' option. WCHAN column shows the name of the kernel function where the process is sleeping:
+'''D''' state occurs then the process is in uninterruptible sleep. This state is bad, because you can't do anything with the process in D state. Fortunately, process normally remains in such state not for so long. But if you have a heap of D state processes then some logic in system is disrupt. If that is happening, the very important thing is to determine where this unlucky sleep occurs. It is easy to do with ps command with ''l'' option. WCHAN column shows the name of the kernel function where the process is sleeping:
 <pre>

@@ Line 19: / Line 19: @@
 <pre>
-# ps axl | grep D
+# ps axl | awk '$10 ~ /D/'
 F   UID   PID  PPID PRI  NI    VSZ   RSS WCHAN  STAT TTY        TIME COMMAND
 vass     13478  7.2  0.0   1732   624 pts/1    D+   17:36   0:00 find ./

@@ Line 1: / Line 1: @@
 If there are a lot of processes in D state in your system, then something is wrong with it.
-What is "D state" and process state in generally? A process in Linux can be in several states: runing state,
-sleeping state and others. Running process runs on a CPU just now, Sleeping process waits for its turn on CPU
+What is '''D state''' and a process state in general? A process in Linux can be in several states: running,
-or for some other event. Using ps command you can obtain information about state of each process in the system: STAT column shows that:
+sleeping, etc. Running process runs on a CPU just now, sleeping process waits for its turn on CPU
 <pre>
-[root@dhcp0-56 ovz-utils]# ps a
+# ps a
    PID TTY      STAT   TIME COMMAND
 tty1     Ss+    0:00 /sbin/mingetty tty1
@@ Line 13: / Line 14: @@
 </pre>
-First big '''S''' stands for Sleeping, '''R''' stands for runing
+First big '''S''' stands for Sleeping, '''R''' stands for running ("+" means that the process is foreground and small "s" means that the process is session leader, but it is not relevant for this article).
-("+" means that the process is foreground and small "s" means that the process is session leader, but it isn't relevant in our discussion).
-D state occurs then the process is in uninterruptable disk sleep. This state is bad, because you can't do anything with the process in D state.
+'''D''' state occurs then the process is in uninterruptible disk sleep. This state is bad, because you can't do anything with the process in D state. Fortunately, process normally remains in such state not for so long. But if you have a heap of D state processes then some logic in system is disrupt. If that is happening, the very important thing is to determine where this unlucky sleep occurs. It is easy to do with ps command with ''l'' option. WCHAN column shows the name of the kernel function where the process is sleeping:
 <pre>
-[root@dhcp0-56 ~]# ps axl | grep D
+# ps axl | grep D
 F   UID   PID  PPID PRI  NI    VSZ   RSS WCHAN  STAT TTY        TIME COMMAND
 vass     13478  7.2  0.0   1732   624 pts/1    D+   17:36   0:00 find ./
 </pre>
-Then you have problem with D state processes always attach this information to the report, that you send to developers.
+{{Note|In case you have problem with the D state processes, always attach this information to the report you send to developers.}}
 [[Category: Troubleshooting]]