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Forum Discussion

cathy_123's avatar
cathy_123
Icon for Cirrostratus rankCirrostratus
Jun 06, 2019

High CPU Utilization CPU1

Hello F5! Would like to ask for possible cause and fix. We have high CPU utlization on CPU1 . It seems it is the systems causing our CPU1 high utilization. Our F5 is in Virtual and in version 12.1...
Rodrigo_Albuque's avatar
Rodrigo_Albuque
Icon for Cirrocumulus rankCirrocumulus
Jun 06, 2019

ah, yeah. I missed that.. sorry.

 

Are you able to take a snapshot of your system and upload to ihealth? https://ihealth.f5.com

 

You can log in to BIG-IP and click on System --> Support.

 

You can then upload your snapshot (called qkview) to ihealth and lastly copy the ihealth link and paste it to us.

 

I can have a quick look at your CPU usage.

Rodrigo_Albuque's avatar
Rodrigo_Albuque
Icon for Cirrocumulus rankCirrocumulus
Jun 06, 2019

Cathy,

 

I see daemon.log is filled with this:

 

Jun 3 04:09:13 seatm1lb001 warning init: serial-ttySX (ttyS0) main process (1257) terminated with status 1

Jun 3 04:09:13 seatm1lb001 warning init: serial-ttySX (ttyS0) main process ended, respawning

Jun 3 04:09:13 seatm1lb001 warning init: Temporary process spawn error: Cannot allocate memory

Jun 3 04:09:40 seatm1lb001 warning init: Temporary process spawn error: Cannot allocate memory

Jun 3 04:15:10 seatm1lb001 warning init: Temporary process spawn error: Cannot allocate memory

 

This matches this bug here: https://cdn.f5.com/product/bugtracker/ID676705.html

 

Any system where the console is not hooked up to /dev/sttyS0 (such as all virtual editions) and where the above bug is not fixed, can experience just high disk usage, not CPU.

 

However, in your case I can see that CPU1 high cpu is caused by system usage and you confirmed that init is eating up cpu cycles so I'd try changing the "respawn" to "off" in /etc/init/serial-ttySX.conf and rebooting the box (make it standby first!)

 

I also see a specific monitor (iweb-serviceadmin_new-4435) going up and down. It would be good to have a look at what is causing it too or at least temporarily disabling it just in case.

 

Cheers.

Rodrigo