Hi, guys,

When I run iostat or vmstat, I find 20% CPU is constantly in sysem mode

 (the sy column in the output). The user mode is less than 2%. In hours

the system runs like that. I am trying to figure out why the machine is

constantly in kernel mode and what it is doing. When I use ps or
prstat, the highest CPU usage of all the processes (including the
system daemons) is around 1%. Most of them are 0.1%. I just don't know
which process is contributing to the 20% kernel mode CPU usage.


The machine is a 8 CPU box running solaris 8. It is a NFS client, not
NFS server.


I read some articles which say if the kernel mode CPu usage is
constantly much hogher than the user mode, most likely the machine has
some problem.


Here come my questions:


1) does CPU usage (%) reported by ps or prstat include the kernel mode
CPU usage, if the process is make system calls?


2) Do we have any way to figure out what the system is busy with?


Thanks.

bill_j_chen@yahoo.com wrote:

>
> 1) does CPU usage (%) reported by ps or prstat include the kernel mode
> CPU usage, if the process is make system calls?

yes

> 2) Do we have any way to figure out what the system is busy with?
>

I like to start with:

/usr/dt/bin/sdtprocess

drop the sample time down to 5 seconds and you will get a good feel for
what is running when and what sort of resources are being used.