sar -d and iostat -x report incorrect disk statistics in Red Hat Enterprise Linux 6

Issue

• iostat -x output shows problems in avgqu-sz data for partitions (the 858992.46 in the output below):

  # iostat -tkxyNd /dev/sdel* 5 1
  05/08/2016 12:04:42 AM
  Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
  sdel              0.00     0.00    0.00    0.20     0.00     1.60    16.00     0.00    1.00   1.00   0.02
  sdel1             0.00     0.00    0.00    0.20     0.00     1.60    16.00 858992.46    1.00 5000.00 100.00
  

• the avgqu-sz for the base block device is not equal to average of all avgqu-sz of partitions on the same block device

• the in-flight field within /proc/diskstats shows a very large, out of expected range, value such as 4294967295