Bug 676237

Summary: iostat: AVG line has sum 0.00 instead of 100.00
Product: Red Hat Enterprise Linux 6 Reporter: Izidor Matušov <imatusov>
Component: sysstatAssignee: Ivana Varekova <varekova>
Status: CLOSED INSUFFICIENT_DATA QA Contact: BaseOS QE - Apps <qe-baseos-apps>
Severity: unspecified Docs Contact:
Priority: medium    
Version: 6.0CC: imatusov, jscotka, ovasik, rvokal
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-05-02 09:24:15 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Izidor Matušov 2011-02-09 07:00:17 UTC
A sanity test for iostat found a bug. With raising command

iostat -cdn 1 60

there is a possibility of having avg-cpu section without meaningful numbers, e.g.:

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           0.00    0.00    0.00    0.00    0.00    0.00

(The expectation is the sum is 100.00 not 0.00)

This malfunction is a quite rare. (it occurs just 3 times in 68077 runs). The problem has been occurring on 3 different RHEL 6.0 machines.

Installed version:
# rpm -qa | grep sysstat
sysstat-9.0.4-11.el6.x86_64

A snippet from iostat -cdn 1 60 output:
<snippet>
Linux 2.6.32-71.el6.x86_64 (pes-02-virt-03.lab.eng.brq.redhat.com) 	02/09/2011 	_x86_64_	(2 CPU)

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
          20.56    1.58   14.43    0.59    0.00   62.85

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
vda              35.41        11.85       743.38    9013978  565258936

Filesystem:              rBlk_nor/s   wBlk_nor/s   rBlk_dir/s   wBlk_dir/s   rBlk_svr/s   wBlk_svr/s     ops/s    rops/s    wops/s

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
          32.20    0.00   23.16    0.56    0.00   44.07

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
vda             179.00         8.00      1720.00          8       1720

Filesystem:              rBlk_nor/s   wBlk_nor/s   rBlk_dir/s   wBlk_dir/s   rBlk_svr/s   wBlk_svr/s     ops/s    rops/s    wops/s

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           0.00    0.00    0.00    0.00    0.00    0.00

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
vda               0.00         0.00         0.00          0          0

Filesystem:              rBlk_nor/s   wBlk_nor/s   rBlk_dir/s   wBlk_dir/s   rBlk_svr/s   wBlk_svr/s     ops/s    rops/s    wops/s

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           2.11    0.00   19.01   66.90    0.00   11.97

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
vda             260.40         0.00      6693.07          0       6760

Filesystem:              rBlk_nor/s   wBlk_nor/s   rBlk_dir/s   wBlk_dir/s   rBlk_svr/s   wBlk_svr/s     ops/s    rops/s    wops/s

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
          51.76    0.00   37.19    0.00    0.00   11.06

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
vda               6.00         0.00        48.00          0         48

Filesystem:              rBlk_nor/s   wBlk_nor/s   rBlk_dir/s   wBlk_dir/s   rBlk_svr/s   wBlk_svr/s     ops/s    rops/s    wops/s

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
          66.33    0.00   32.16    0.00    0.00    1.51

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
vda              12.00         0.00        96.00          0         96

Filesystem:              rBlk_nor/s   wBlk_nor/s   rBlk_dir/s   wBlk_dir/s   rBlk_svr/s   wBlk_svr/s     ops/s    rops/s    wops/s

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
          71.50    0.00   24.00    0.00    0.00    4.50

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
vda              19.00         0.00       152.00          0        152

Filesystem:              rBlk_nor/s   wBlk_nor/s   rBlk_dir/s   wBlk_dir/s   rBlk_svr/s   wBlk_svr/s     ops/s    rops/s    wops/s

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
          18.59    0.00    5.53    0.00    0.00   75.88

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
vda               5.00         0.00        40.00          0         40

Filesystem:              rBlk_nor/s   wBlk_nor/s   rBlk_dir/s   wBlk_dir/s   rBlk_svr/s   wBlk_svr/s     ops/s    rops/s    wops/s

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           0.00    0.00    0.51    0.51    0.00   98.99

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
vda               9.00         0.00      3968.00          0       3968

Filesystem:              rBlk_nor/s   wBlk_nor/s   rBlk_dir/s   wBlk_dir/s   rBlk_svr/s   wBlk_svr/s     ops/s    rops/s    wops/s

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           0.00    0.00    0.00    0.00    0.00  100.00
</snippet>

Comment 2 Ondrej Vasik 2011-02-09 14:49:11 UTC
Does this ever happened even when you use longer interval? I mean 2 seconds?

Comment 4 Brock Organ 2011-03-01 14:43:11 UTC
Reporter,

Could I please ask you to provide a priority assessment (set the priority field to one of urgent/high/medium/low) for the impact of this issue?  This will help us prioritize this issue with our other outstanding bugs for the current release cycle ...

Regards,

Brock

Comment 5 Ivana Varekova 2011-05-02 09:24:15 UTC
Hello,
the debug data are necessary to fix this issue, thus now I'm closing this bug for insufficient data. Please reopen if you get the log files, reopen this issue and put the files here.