topic Re: CPU idle is 0% in Operating System - Linux

cpu idel is 0%

jona_1 — Sat, 26 Feb 2011 20:30:52 GMT

Hi,
In one of our server CPU idel is always showing 0%.Always.

RHEL 4 (Nahant update 6)
2.6.9-89.EL

I have checked & found 2/3 defunct process are there.Each of those are taking 5.5% of cpus.Does the defunct process taking the cpu?
Shall i go for reboot?how to find who is eating the cpu?

Regards,

Re: CPU idle is 0%

Dennis Handly — Mon, 22 Aug 2011 00:51:06 GMT

>Does the defunct process taking the CPU? Shall I go for reboot?

No, zombies don't take up CPU time.
If you kill the zombie master, the zombies will be reaped.

>how to find who is eating the CPU?

Does the system seem busy?

Re: cpu idel is 0%

jona_1 — Sun, 27 Feb 2011 08:16:38 GMT

HI,
Thank you so much. you are the only person who reply..I am doing remote administration..
I think only one CPU is present in this system...I am sending you one attachment ... could you please look into this ....really appreciate your cooperation if you could suggest me what i should do now to reduce the cpu util....waiting for reply..

Regards,
Jona

Re: CPU idle is 0%

Dennis Handly — Mon, 22 Aug 2011 00:51:49 GMT

>I am sending you one attachment ... Could you please look into this. If you could suggest me what I should do now to reduce the CPU util

I don't see much CPU usage, 20% including those bogus zombies.

Again, why do you think there is a problem?
Do you have a lot of I/O activity?

Re: cpu idel is 0%

jona_1 — Mon, 28 Feb 2011 03:31:06 GMT

Thank you.In top CPU idel is 0% sothat i am worried....every time it is 0%.idel is 0% that means 100% utilization...

Regards,
Jona

Re: CPU idle is 0%

Dennis Handly — Mon, 22 Aug 2011 00:52:12 GMT

>In top CPU idle is 0%.

The top output you attached showed: 93.3% id

Re: cpu idel is 0%

jona_1 — Mon, 28 Feb 2011 06:22:45 GMT

Thank you Dennis , yes you are right cpu util is 93% idel now.. ...but another problem come with this server ..could u pls help me to understand this....we are receiving this msg like

"with description THRESHOLD (Total Free Memory (MB)): Total (42xx.xx > 98.0 ) [Running Command ux_)"

unable to understand the above msg:-

-sh-3.00$ free -tm
total used free shared buffers cached
Mem: 3885 3802 82 0 50 181
-/+ buffers/cache: 3570 315
Swap: 4251 64 4186
Total: 8136 3867 4269
-sh-3.00$
Free mem is 4269MB then what is the problem ..is it too low?

Regards,

Re: CPU idle is 0%

Dennis Handly — Mon, 22 Aug 2011 00:52:34 GMT

>Free mem is 4269MB

That's 4.2 Gb for total swap. Free memory is just 82 Mb.

Re: cpu idel is 0%

jona_1 — Mon, 28 Feb 2011 09:08:58 GMT

Hi Dennis,
From this command i have checked that the Java process is using 15% of memory

-sh-3.00$ ps aux | awk '{print $4"\t"$11}' | sort | uniq -c | awk '{print $2" "$1" "$3}' | sort -nr
please find the attachment..now is there any parameter from which we can tune.. or how to increase the free memory ..
4 zombi process are there also ..
Regards,
jona

Re: cpu idel is 0%

jona_1 — Mon, 28 Feb 2011 09:30:38 GMT

just now came to know from some team that its a linux VM

Re: CPU idle is 0%

Dennis Handly — Mon, 22 Aug 2011 00:52:56 GMT

>the Java process is using 15% of memory
>now is there any parameter from which we can tune or how to increase the free memory

Why do you think you need more free memory? Is the system slow? You want to run more apps?
If you have a lot in your buffers/cache, the kernel will reduce that when you need more memory.

>4 zombie process are there also

You need to determine which is more important, getting rid of the zombies or to keep the zombie master alive.