IY61147: SAR -D SHOWS NEGATIVE VALUES

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Problem:
  
  The sar command displays negative  values in the
  scenario created by the following shell script:
  
  #!/bin/sh
  
  #generate transfers from or to a device
  while :
  do
  cp /unix /tmp/$$tmp
  rm /tmp/$$tmp
  done &
  
  pid=$!
  
  #set the iostrun flag to false
  #this command terminates under
  #execution of the following sar command.
  chdev -l sys0 -a iostat=false
  
  #execute the iostat command
  iostat 1 6  > /dev/null &
  
  #sleep 1
  
  #execute the sar command with d option
  sar -d 1 4
  #sar -d 2 3 &
  
  sleep 6
  
  #stop transfers
  kill $pid
  
  REASON:
  The iostat command completes its execution and
  sets back the iostat flag value to false(its initial value)
  which turns off the Disk I/O History.
  When the Disk I/O History is turned off,
  sadc (internally called by sar) reports zeros.
  sar uses these statistics and subtracts it with the
  statistics obtained in earlier iteration to get the
  current disk statistics.
  As a result of this, sar -d gives negative values.
  

Local fix

Problem summary

• sar -d shows negative values.
  

Problem conclusion

• code changes made to fix the problem.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  IY61136

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  AIX 5L POWER V5

• Fixed component ID

  5765E6200

Applicable component levels

• R520 PSY U477811

     UP04/12/17 I 1000

PTF to Fileset Mapping

• U477811 bos.acct 5.2.0.51