topic Re: 100% CPU Usage running linux commands in Operating System - Linux

100% CPU Usage running linux commands

KarloChacon — Tue, 10 Jan 2012 21:19:28 GMT

hi

the application guy told me that his server was executing linux commands with some delay...let's say 1-2-3 seconds after the command is execute the output is shown

checking the system we found that when the delay took place CPU usage for that command in top was 100%.... this happens for bash, chkconfig, w, df, du among others in fact when you start working with command load average is normal and after executing commands load average is the double amount in CPU Usage

has someone seen this before? a know issue?
something to check?

important to note is this the Red Hat Release is 5.4 Beta which I think is not good but the system was working fine until last week
by the way is it recommended to upgrade from Red Hat 5.4 Beta to 5.4 final release? or even 5.5?

I mean going from beta to a final release is OK?

thanks a lot guys

Re: 100% CPU Usage running linux commands

Matti_Kurkela — Wed, 11 Jan 2012 11:53:43 GMT

Check the health of the server's disks ASAP. One possible reason for that kind of behavior is that the system disk is failing but still manages to provide the requested information after a number of retries.

(If the system disk is mirrored but the health of the mirror is not monitored, one half of the mirror might already have completely failed, and the other half might now be failing too...)

Things to check:

- dmesg (any disk errors or other serious-looking things visible?)

- any hardware RAID status, if you have them (usually hardware-type-specific utility, e.g. for HP SmartArray RAID controllers, "hpacucli ctrl all show config detail" would list all information on every SmartArray controller installed on the system. You would check the "Status:" fields on all listed logical & physical drives.)

- if you have NFS-mounted filesystems, are the NFS servers overloaded? (If your PATH environment variable includes NFS-mounted directories, and the NFS server is overloaded or down, you might see slowdown with many commands.)

Re: 100% CPU Usage running linux commands

KarloChacon — Wed, 11 Jan 2012 14:58:42 GMT

I don't see anything related with disks on dmesg

space on disks look ok

Filesystem Size Used Avail Use% Mounted on

/dev/mapper/VolGroup00-LogVol00 28G 3.4G 23G 13% /
/dev/sda1 99M 13M 82M 14% /boot
tmpfs 3.9G 0 3.9G 0% /dev/shm

/dev/mapper/VolGroup00-LogVol02 40G 34G 3.7G 91% /mxapps

see dmesg attached

and no everything is local disks no NFS I will have tro send someone to check any fail status on disk, this is a IBM server I and I think dont hace the RAID utilities

thanks a lot

Re: 100% CPU Usage running linux commands

Alzhy — Tue, 17 Jan 2012 20:10:05 GMT

post output of:

sar 5 5

sar -d 5 5

vmstat 5 5

free