I noticed when i type top there is always zombie tasks which dissaper and appear.Is that bad,if yes how do i get rid of them and detect what causing them ?

This site has some good info on what Zombie processes are. It looks like you have a program(s) running somewhere that is a little slow at collecting its dead baby processes with wait() So no problem

This is by design. No action is necessary on your part. There is nothing wrong. "Nothing to see here... move along... move along..."

The Unix/Linux system is founded on the notion that you can get things done by creating small, simple, fairly special-purpose programs and stringing them together. For example, the command-line features '|' ("pipe") and '&' ("background execution") are built on this.

So... you (or your program) fires-off another process to do this-or-that, and then, say, waits for it to finish. (Or, eventually notices that it has finished.)

Thought Question... When that 'other process' finishes, it becomes a "zombie" precisely so that it will be possible for your process to "notice that it has died" and to collect final-status (such as a return-code) from it.

The "zombie" state exists to facilitate this rendezvous.

The "zombie" sits there until you inquire. The act of "waiting for the 'other process' to die," or of "noticing that it has died," serves to reap ... as in Grim Reaper ... the zombie-process. At this point, the zombie ceases to exist.

If your process dies without inquiring as to the status of the others, the zombies will be inherited by "process #1, 'init'," a system-defined process which by-definition never dies. init will, of course, immediately "reap" them.

(Process-table overflows are prevented by imposing reasonable limits on the maximum number of processes, "dead or alive," that you can have.)

In shortly i dont need to bother with it.

1- eating brains
2- walking around going "ugghhhnnnnn"
3- scaring people
4- most find work in movies.



I could not resist....

I like "zombie movies," and some of those really-campy movies that occupied many a too-hot afternoon in (uhhh....) the mid-80's.

My favorite, I guess, was named Hotel Hell. The name ostensibly came from the fact that the "O" of "Hello" was burned-out. Believe me, the movie took a real nose-dive from there. But what made it so darned funny to me was that it was not trying to be funny: it was trying to be scary.

You know the formula. Basically, the story goes that for some reason people were getting their vocal-cords ripped out and they got planted up to their necks in the garden, still alive and making gagging noises. And then this cute young couple (TM) has their car break down on a lonely rainy night (TM) and ... blah blah blah. Well, let's just say that "Psycho it ain't. But it did beat being outside in the heat."

Thanks sundialscvs. I always wondered that myself.

The zombie state is the final state of any given process, or, more accurately, the "nonexistence". A process marked as zombie is a process that have been closed. It no longer exists in the memory and all the associated structures have been freed.

The concept of "process" only loosely applies to a "zombie process".

So, what's exactly what remains? The name of the process in the process table, and the associated return value of that process, which can be useful for many purposes. You don't have to worry about zombie processes, it's just the normal way of handling processes in linux.