The paging activity of the hypervisor can be monitored in a shared memory LPAR. AIX provides a number of options for this. In this way, it is possible to monitor how much physical memory is currently allocated to the LPAR, how many pages have so far been paged-in again by the hypervisor and how much time delay has arisen as a result.

The “lparstat -m” command can be used to display shared memory statistics under AIX:

aix22 # lparstat -m 1
 
System configuration: lcpu=16 mem=2048MB mpsz=1.00GB iome=351.00MB iomp=11 ent=0.20 
 
physb   hpi  hpit  pmem  iomin   iomu   iomf  iohwm iomaf %entc  vcsw 
----- ----- ----- ----- ------ ------ ------ ------ ----- ----- ----- 
16.39     1     1  0.68  302.1   10.9   48.9   12.5     0 205.3  2708 
 0.27     0     0  0.68  302.1   10.9   48.9   12.5     0  12.5   609 
 0.22     0     0  0.68  302.1   10.9   48.9   12.5     0   7.4   581 
 9.80    96    30  0.68  302.1   10.9   48.9   12.5     0 100.4  1504 
54.80     0     0  0.68  302.1   10.9   48.9   12.5     0 589.7  7024 
81.46     1     1  0.68  302.1   10.9   48.9   12.5     0 907.1 11204 
81.45     1     0  0.68  302.1   10.9   48.9   12.5     0 913.5 11236 
79.88     0     0  0.68  302.1   10.9   48.9   12.5     0 911.6 10862 
25.20     0     0  0.68  302.1   10.9   48.9   12.5     0 313.4  3839 
 0.20     0     0  0.68  302.1   10.9   48.9   12.5     0   6.8   426 
^C
aix22 #

Among other things, the following attributes are displayed:

• • mpsz – size of the shared memory pool
  • hpi – number of hypervisor page-ins
  • hpit – time consumed for the hypervisor page-ins in milliseconds
  • pmem – allocated physical memory in GB
  • …

Similar information can also be obtained with the vmstat command and the ‘-h‘ option, e.g.:

aix22 # vmstat -h -v
               524288 memory pages
               495111 lruable pages
                 2079 free pages
                    2 memory pools
               206873 pinned pages
                 90.0 maxpin percentage
                  3.0 minperm percentage
                 90.0 maxperm percentage
                  3.0 numperm percentage
                15311 file pages
                  0.0 compressed percentage
                    0 compressed pages
                  3.0 numclient percentage
                 90.0 maxclient percentage
                15311 client pages
                    0 remote pageouts scheduled
                    0 pending disk I/Os blocked with no pbuf
                    0 paging space I/Os blocked with no psbuf
                 2228 filesystem I/Os blocked with no fsbuf
                   47 client filesystem I/Os blocked with no fsbuf
                    0 external pager filesystem I/Os blocked with no fsbuf
                11129 Virtualized Partition Memory Page Faults
                 6437 Time resolving virtualized partition memory page faults
               278409 Number of 4k page frames loaned
                   53 Percentage of partition memory loaned
                 96.7 percentage of memory used for computational pages
aix22 #

The topas command has been expanded to include the ‘-L‘ option, to provide similar informations.