A “zombie process” is an entry in the process table corresponding to a dead process. The entry will be remove when the process's parent checks its child's return status.
Questions tagged [zombie-process]
39 questions
28
votes
3 answers
How can I kill a process whose parent is init?
Transmission is intermittently hanging on my NAS. If I send SIGTERM, it doesn't disappear from the process list and a label appears next to it. If I send a SIGKILL, it still doesn't disappear and I can't terminate the parent because the…
Andy E
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2 answers
Can a zombie have orphans? Will the orphan children be disturbed by reaping the zombie?
As I understand it, a zombie process has died but still exists as a placeholder in the process table until its parent (or init if the zombie is itself an orphan) checks its exit status.
And my understanding of orphan processes is they are processes…
Wildcard
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Why Process/program becomes zombie?
If script is running fine from command line then, why the same script becomes zombie state after running through cron and How you will troubleshoot the same ?
Here following real example :
[root@abc ~]# ps ax | grep Z
23880 ? Zs 0:00…
Rahul Patil
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16
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3 answers
Is there an upper limit to the number of zombie processes you can have?
I used to work with an HP-UX system and the old admin told me there is an upper limit on the number of zombie processes you can have on the system, I believe 1024.
Is this a hard fact ceiling? I think you could have any number of zombies just as…
ProfessionalAmateur
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14
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4 answers
How to kill a process which can't be killed without rebooting?
There are 5 processes which can't be killed by kill -9 $PID and executing cat /proc/$PID/cmdline will hang the current session. Maybe they're zombie processes.
Executing ps -ef or htop will also hang the current session. But top and ps -e are…
Sam Stoelinga
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13
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4 answers
How does linux handles zombie process
Zombie processes are created in Unix/Linux systems.
We can remove them via the kill command.
But is there any in-built clean-up mechanism in Linux to handle zombie processes?
Atur
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12
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Why is a zombie waiting for its child?
I'm digging through different sources, but can't find a good description of the anatomy of child reaping. This is a simple case of what I would like to understand.
$ cat <( sleep 100 & wait ) &
[1] 14247
$ ps ax -O pgid | grep $$
12126 12126 S…
user147505
11
votes
2 answers
What happends when sending SIGKILL to a Zombie Process in Linux?
In Linux, when a child process terminates and it's parent has not yet waited on it, it becomes a zombie process. The child's exit code is stored in the pid descriptor.
If a SIGKILL is sent to the child, there is not supposed to be any effect.
Does…
user137481
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9
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3 answers
Background, zombie, daemon and without ctty - are these concepts connected?
How these process concepts are related together - background, zombie, daemon and without controlling terminal?
I feel that they are somehow close, especially through the concept of controlling terminal, but there is still not much info for me to…
anatoly techtonik
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7
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1 answer
How to kill - softly?
If I want to kill a process as careful and politely as possible,
which signals should I use in a kill command, in which order?
I would like to give the programm any kind of time to clean up, if it likes to, so just sending a SIGTERM will be to…
Volker Siegel
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6
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6 answers
Is there a way to identify which process turns into Zombie process
One of the ubuntu server has 82 zombie processes. All processes shows '[sh] defunct' as process command. Is there a way to find out which process is becoming a zombie process?
I tried checking the /proc/PID/ directory to get some clue about zombie…
user379997
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2 answers
Removing zombie process from the process table
Can somebody please explain when parent process receives the exit status of a dead child process via wait, who actually reallocates the memory of the child process and removes it from the process table?
macindows
4
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2 answers
Why or how does killing the parent process clean the zombie child processes in linux?
Consider this example -
#include
#include
#include
int main()
{
pid_t pid = fork();
if (pid > 0)
{
printf("Child pid is %d\n", (int)pid);
sleep(10);
system("ps -ef | grep defunct | grep -v grep");
}
…
shawdowfax1497
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4
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zombie process reap without "wait"
I know if a subprocess does not get reaped properly, it will become a zombie and you can see it by ps command.
Also the "wait [pid]" command will wait for subshell running on the background until it finishes and reap it.
I have a script like…
chengdol
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processes remain behind
I have an embedded system that was going non-responsive after running for several hours. After investigating I found that the system kept growing a list of processes. Running ps axl gives a long list a snippet of which is as follows:
1 …
arshan
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