[hobbit] Solaris vmstat and sar

[Lund, Holly]

vmstat first output is invalid.  doing vmstat 5 5 the other 4 should
change to reflect sar


Holly Lund
301-903-1174
202-586-4431

-----Original Message-----
From: James Wade [mailto:jkwade at futurefrontiers.com] 
Sent: Monday, December 03, 2007 1:55 PM
To: hobbit at hswn.dk
Subject: RE: [hobbit] Solaris vmstat and sar

I agree with you, but the snapshots that I emailed were taken

at the same time.

 

I'm now graphing both Sar CPU Utilization, and Hobbit CPU Utilization

which uses vmstat.  SAR shows the more correct CPU Utilization as
compared

to CPU Load (uptime). Also, "TOP" confirms that CPU is loaded. I have

a multi-cpu version of top I use and all the CPU's are max'd with 1% or
2% idle.

 

During this timeframe, cpu utilization using vmstat shows 67% idle..

 

I've seen this problem for a while now on multiple systems, but I just
recently

wrote my own sar script to put sar cpu into hobbit graphs to confirm
this.

 

Here's where I just did a 5 minute average in two different windows on
the same box

at the same time: vmstat shows 67% idle, sar, 26% idle:

 

vmstat 300 2

 kthr      memory            page            disk          faults
cpu

 r b w   swap  free  re  mf pi po fr de sr s3 s3 s9 s1   in   sy   cs us
sy
id

 0 4 0 68896560 24040168 673 3181 1548 15 14 0 0 12 12 0 0 12938 44125
19506
18 15 67

 0 4 0 68896480 24040352 673 3181 1548 15 14 0 0 12 12 0 0 12942 44130
19525
18 15 67

 

$ sar 300 1

 

12:44:17    %usr    %sys    %wio   %idle

12:49:17      31      32      11      26

 

TOP shows sar is correct:

 

load averages: 18.56, 17.41, 17.71
12:54:14

866 processes: 836 sleeping, 1 running, 7 stopped, 22 on cpu

CPU states: 14.6% idle, 36.6% user, 32.4% kernel, 16.5% iowait,  0.0%
swap

Memory: 48G real, 24G free, 18G swap in use, 65G swap free

 

James

 

  _____  

From: Lars Ebeling [mailto:lars.ebeling at leopg9.no-ip.org]
Sent: Monday, December 03, 2007 12:28 PM
To: hobbit at hswn.dk
Subject: Re: [hobbit] Solaris vmstat and sar

 

Hello,

 

I don't think you should compare like that. They are snapshots and only
reflecting the status at that moment.

 

I did vmstat -n 5 5 on HP-UX and got:

VM

       memory                     page                          faults

     avm    free   re   at    pi   po    fr   de    sr     in     sy
cs

   65466    9823   22    8     2    0     0    0     1    113      3
139

CPU

    cpu          procs

 us sy id    r     b     w

 37  4 60    2     0     0

   65466    9675    6    4     1    0     0    0     0    113    377
87

  2  1 96    2     0     0

   71121    8536  174   43     5    0     0    0     0    117   6766
142

 23 13 65    2     4     0

   71121    8991  201   98     3    0     0    0     0     98   8594
238

 65 24 12    2     4     0

   84056    8990   86   34     1    0     0    0     0    103   3979
120

  5  3 92    5     1     0

#


 

Here you can see that idle varies 60% 96% 65% 12% 92%

 

 

Regards

Lars

----- Original Message ----- 

From: James <mailto:jkwade at futurefrontiers.com>  Wade 

To: hobbit at hswn.dk 

Sent: Monday, December 03, 2007 7:10 PM

Subject: [hobbit] Solaris vmstat and sar

 

All,

 

Solaris vmstat is crummy for CPU Utilization.

 

If I do a vmstat on a Solaris box that's having high load,

I get 67% idle, yet sar shows 3% idle.

 

Has anyone seen this before?

 

sar -u 1 1

 

12:08:40    %usr    %sys    %wio   %idle

12:08:41      46      44       6       4

 

 

vmstat 1 1

 kthr      memory            page            disk          faults
cpu 
r b w   swap  free  re  mf pi po fr de sr s3 s3 s9 s1   in   sy   cs us
sy
id
 0 4 0 68897248 24039040 673 3180 1550 15 14 0 0 12 12 0 0 12901 44078
19363
18 15 67

So, what's the work around because Hobbit is using vmstat?

James