PS: you cannot use
on a defunct (zombie) process, because the process is already dead.
The name zombie comes from those cheap 1960's movies like 'Day of the Dead' - except in those movies you could apparently 'kill' those zombies.... you cannot kill something that is already dead in UNIX, it ain't the movies.
These 3 Users Gave Thanks to jim mcnamara For This Post:
When I ps -ef I see about 3 or 4 <DEFUNCT> things - what are these, and what causes them? Are they a concern? How can I fix them?
Thanks,
Michael (4 Replies)
Hey guys/gals. I am new to the site and fairly new to Unix/Linux. I have a master netbackup server (solaris) that I get pinged on occasionally regarding defunct processes. (Usually over 50 or so of them.) I know what a defunct process is, but what is it a product of? Just plain sloppy code? (From... (1 Reply)
Hi,
Can any one help me to get rid of defunct process on UNIX IBM AIX box. These processes started when the system was rebooted almost after 1 1/2 years. Once one defunct process is created then all the user ids get infected and in turn creates numerous defunct processes. We have tried... (6 Replies)
hello everybody!
Is there any way to identify if a process is defunct or if it is still running? (in C).
for example: by using a signal such as SIGCHLD?
thanx in advance (1 Reply)
Hi All,
Sorry to bother you all if my query is silly. Can you please clarify my doubts on defunct processes.
Actually coming to the scenario, i have a server which is under cluster environment. Server B is having problems with the defunct process. There was a cron scheduled on Server B which... (0 Replies)
Dear Sir / Madam,
We have two socket programs which are running in background. These two socket programs are creating defunct processes in HP-UX which were not happening in Compaq True64 UNIX. What is the root cause of these defunct processes and how can we correct it?
Your suggestion will be... (3 Replies)
HiI had a tool fail recently, on analysis I found it was cleaning up orphaned directories that had been created by specific processes that had died for some reason, thus failing to clean up after themselves.The directories were of the form /dir.pid. The tool would look to see if any instances of... (2 Replies)
I'd like to remove this defunct processes without rebooting. Or, I could remove this defuncts when the maximum allowable process is nearly reached, then send an email to the user/team. How can I determine the maximum allowable process that a server can handle? Any thoughts?
Jin@PRODUCTION: >... (3 Replies)
Discussion started by: Jin_
3 Replies
LEARN ABOUT LINUX
preap
preap(1) User Commands preap(1)NAME
preap - force a defunct process to be reaped by its parent
SYNOPSIS
preap [-F] pid...
DESCRIPTION
A defunct (or zombie) process is one whose exit status has yet to be reaped by its parent. The exit status is reaped via the wait(3C),
waitid(2), or waitpid(3C) system call. In the normal course of system operation, zombies may occur, but are typically short-lived. This may
happen if a parent exits without having reaped the exit status of some or all of its children. In that case, those children are reparented
to PID 1. See init(1M), which periodically reaps such processes.
An irresponsible parent process may not exit for a very long time and thus leave zombies on the system. Since the operating system destroys
nearly all components of a process before it becomes defunct, such defunct processes do not normally impact system operation. However, they
do consume a small amount of system memory.
preap forces the parent of the process specified by pid to waitid(3C) for pid, if pid represents a defunct process.
preap will attempt to prevent the administrator from unwisely reaping a child process which might soon be reaped by the parent, if:
o The process is a child of init(1M).
o The parent process is stopped and might wait on the child when it is again allowed to run.
o The process has been defunct for less than one minute.
OPTIONS
The following option is supported:
-F Forces the parent to reap the child, overriding safety checks.
OPERANDS
The following operand is supported:
pid Process ID list.
EXIT STATUS
The following exit values are returned by preap, which prints the exit status of each target process reaped:
0 Successfully operation.
non-zero Failure, such as no such process, permission denied, or invalid option.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWesu (32-bit) |
+-----------------------------+-----------------------------+
| |SUNWesxu (64-bit) |
+-----------------------------+-----------------------------+
SEE ALSO proc(1), init(1M), waitid(2), wait(3C), waitpid(3C), proc(4), attributes(5)WARNINGS
preap should be applied sparingly and only in situations in which the administrator or developer has confirmed that defunct processes will
not be reaped by the parent process. Otherwise, applying preap may damage the parent process in unpredictable ways.
SunOS 5.10 26 Mar 2001 preap(1)