Incorrect information repported by blktrace via btt utility on RHEL 5

Solution Unverified - Updated -

Issue

  • using blktrace data via btt -I report shows extremely high avgrq-sz (5th field back from end of line)
  • using blktrace data via btt -I report shows extremely high avgqu-sz:
Device:       rrqm/s   wrqm/s     r/s     w/s    rsec/s    wsec/s     rkB/s     wkB/s avgrq-sz avgqu-sz   await   svctm  %util   Stamp
( 65, 64)       0.00     0.00 1732.90  679.11  27726.34  17984.65  13863.17   8992.33    18.95 265582.21    0.41    0.41  73.73  105.83
  • I2D overhead time is reported as >200% from btt:
==================== Device Overhead ====================

       DEV |       Q2G       G2I       Q2M       I2D       D2C
---------- | --------- --------- --------- --------- ---------
 ( 65, 64) |   0.3658%   2.9935%   0.0001% 220.9209%  91.1301%

Environment

  • Red Hat Enterprise Linux 5

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