AIX Tip of the Week

Subject: Monitoring Overall CPU Utilization in a Power5 Micropartitioned Server

Audience: All

Date: October 8, 2005

The "lparstat" command shows the available physical processors in the shared pool on a Power5 micropartitioned server.

The lparstat command can be run from any logical partition that has enabled "Allow shared processor pool utilization authority" **. The following lparstat output shows 10 measurements taken at 5 second intervals. The size of the shared pool is 2 CPU's (psize). The available processors for each sample interval is shown under the "app" column. The first line under the app column shows 0.65 available processors. The CPU utilization in this interval is 67.5% ( (2.0 - 0.65) / 2.0 )

# lparstat 5 10                                                      
                                                                                
System configuration: type=Shared mode=Uncapped smt=On lcpu=4 
mem=1024 psize=2 ent=0.20                                                                         
                                                                                
%user  %sys  %wait  %idle physc %entc  lbusy   app  vcsw phint                  
-----  ----  -----  ----- ----- ----- ------   ---  ---- -----                  
  0.3  13.2    0.0   86.5  0.03  17.4    7.0  0.65   697     3                  
  1.3   8.0    0.0   90.7  0.02  12.5    3.1  0.70   625     3                  
 10.3  55.0    0.2   34.5  0.20  98.2   15.2  0.45 10533     9                  
  6.5  36.8    0.0   56.7  0.13  64.4    6.2  0.33  6234    11                  
  3.0   5.5    0.0   91.5  0.02  12.0    0.0  0.91   556     4                  
 12.7  27.0    0.0   60.3  0.10  52.4    2.3  1.23  1855     7                  
 17.3  28.0    0.0   54.7  0.12  58.7    4.1  1.22  1687    10                  
  1.3  10.6    0.0   88.1  0.03  16.6    1.0  1.58   898     4                  
  9.0  19.0    0.6   71.3  0.08  40.0    4.6  1.26  1844     8                  
  6.1  15.6    0.0   78.3  0.06  31.6    1.6  1.31  1633     7                  

**The "Allow shared processor pool utilization authority" is enabled from the HMC. "Right click" the partition name (not the profiles) and choose "Properties". Go to the "Processors and Memory" tab. Check the "Allow shared processor pool".


Bruce Spencer,
baspence@us.ibm.com

October 8, 2005