[hobbit] vmstat graphing with CPU io wait

[Tom Georgoulias]

Henrik Storner wrote:

<snip>

Thanks for the explanation of larrd.  It helped a lot.

> Where do you get the I/O wait information from ?

On RHEL3 (procps-2.0.17-10), there is a value for it in column 14 of 
vmstat's output, labeled "wa" under "cpu", so I modified a section of 
larrd-0.43c's vmstat-larrd.pl so it'd recognize this value and use it 
when dealing with rhel3 systems.  I hacked my client's vmstat larrd bf 
script to make it determine if the system rhel3 or not, then exported 
the BBOSNAME as rhel3 so this array assignment would used by 
vmstat-larrd.pl.

rhel3 => {  cpu_r    => 0,
	cpu_b    => 1,
	mem_swpd => 2,
	mem_free => 3,
	mem_buff => 4,
	mem_cach => 5,
	mem_si   => 6,
	mem_so   => 7,
	dsk_bi   => 8,
	dsk_bo   => 9,
	cpu_int  => 10,
	cpu_csw  => 11,
	cpu_usr  => 12,
	cpu_sys  => 13,
	cpu_wait => 14,
	cpu_idl  => 15,

I might try adding this to hobbitd/larrd/do_vmstat.c and see if I can 
make it work.

>      DEF:cpu_idl=vmstat.rrd:cpu_idl:AVERAGE
> 
> i.e. grab the "vmstat.rrd" file, and extract the current average value
> of the "cpu_idl" dataset.

> You can mix values from different RRD files in the same graph,
> e.g. the "vmstat2" graph uses both the "vmstat.rrd" file and the
> "la.rrd" file:
> 

This is nice.  Once I figured out what you were doing there, I thought 
"hey, all I've got to do is set up a def for cpu_wa|cpu_wait and I'm 
golden."  Then I fired up rrdtool and checked the rrd file, only to 
realize that I didn't have the data to begin with...

> If you have more questions, please ask. And if you have something that
> could be of interest to others, I'll be happy to include it with
> Hobbit.

I'll be happy to contribute any patches that I generate.

Tom

Tom