| Summary: | first iteration of iostat in sysstat 7.0.2 appears to report artificially low results | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 5 | Reporter: | William Yardley <wby+redhat> |
| Component: | sysstat | Assignee: | Peter Schiffer <pschiffe> |
| Status: | CLOSED NOTABUG | QA Contact: | BaseOS QE - Apps <qe-baseos-apps> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 5.7 | CC: | wby+redhat |
| 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: | 2012-02-20 10:59:56 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
William Yardley
2012-02-16 19:52:04 UTC
Running iostat over and over gives me the same %iowait, %user, etc. values consistently:
water-griffen:$ iostat
Linux 2.6.18-274.7.1.el5PAE (water-griffen.caltech.edu) 02/16/2012
avg-cpu: %user %nice %system %iowait %steal %idle
1.28 0.00 1.43 3.55 0.00 93.74
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 38.47 4.20 536.10 13127193 1675426004
sda1 0.00 0.00 0.00 424 0
sda2 0.00 0.00 0.00 500 0
sda3 0.00 0.00 0.00 3282 6948
sda4 0.00 0.00 0.00 6 0
sda5 38.47 4.20 536.10 13112602 1675418496
sda6 0.00 0.00 0.00 1459 560
water-griffen:$ iostat
Linux 2.6.18-274.7.1.el5PAE (water-griffen.caltech.edu) 02/16/2012
avg-cpu: %user %nice %system %iowait %steal %idle
1.28 0.00 1.43 3.55 0.00 93.74
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 38.47 4.20 536.10 13127193 1675426540
sda1 0.00 0.00 0.00 424 0
sda2 0.00 0.00 0.00 500 0
sda3 0.00 0.00 0.00 3282 6948
sda4 0.00 0.00 0.00 6 0
sda5 38.47 4.20 536.10 13112602 1675419032
sda6 0.00 0.00 0.00 1459 560
water-griffen:$ iostat
Linux 2.6.18-274.7.1.el5PAE (water-griffen.caltech.edu) 02/16/2012
avg-cpu: %user %nice %system %iowait %steal %idle
1.28 0.00 1.43 3.55 0.00 93.74
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 38.47 4.20 536.10 13127193 1675426540
sda1 0.00 0.00 0.00 424 0
sda2 0.00 0.00 0.00 500 0
sda3 0.00 0.00 0.00 3282 6948
sda4 0.00 0.00 0.00 6 0
sda5 38.47 4.20 536.10 13112602 1675419032
sda6 0.00 0.00 0.00 1459 560
And, running iostat 5 shows about that same value on the first iteration, and the (apparently) correct value on subsequent iterations:
water-griffen:$ iostat 5
Linux 2.6.18-274.7.1.el5PAE (water-griffen.caltech.edu) 02/16/2012
avg-cpu: %user %nice %system %iowait %steal %idle
1.27 0.00 1.43 3.55 0.00 93.74
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 38.46 4.19 536.06 13099411 1675095524
sda1 0.00 0.00 0.00 424 0
sda2 0.00 0.00 0.00 500 0
sda3 0.00 0.00 0.00 3276 6940
sda4 0.00 0.00 0.00 6 0
sda5 38.46 4.19 536.06 13084826 1675088024
sda6 0.00 0.00 0.00 1459 560
avg-cpu: %user %nice %system %iowait %steal %idle
3.16 0.00 4.01 29.28 0.00 63.56
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 41.60 30.40 604.80 152 3024
sda1 0.00 0.00 0.00 0 0
sda2 0.00 0.00 0.00 0 0
sda3 0.00 0.00 0.00 0 0
sda4 0.00 0.00 0.00 0 0
sda5 41.60 30.40 604.80 152 3024
sda6 0.00 0.00 0.00 0 0
avg-cpu: %user %nice %system %iowait %steal %idle
3.13 0.00 3.41 27.75 0.00 65.71
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 43.60 0.00 667.20 0 3336
sda1 0.00 0.00 0.00 0 0
sda2 0.00 0.00 0.00 0 0
sda3 0.00 0.00 0.00 0 0
sda4 0.00 0.00 0.00 0 0
sda5 43.60 0.00 667.20 0 3336
sda6 0.00 0.00 0.00 0 0
avg-cpu: %user %nice %system %iowait %steal %idle
4.52 0.00 5.04 27.72 0.00 62.72
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 64.40 1.60 870.40 8 4352
sda1 0.00 0.00 0.00 0 0
sda2 0.00 0.00 0.00 0 0
sda3 0.00 0.00 0.00 0 0
sda4 0.00 0.00 0.00 0 0
sda5 64.40 1.60 870.40 8 4352
sda6 0.00 0.00 0.00 0 0
avg-cpu: %user %nice %system %iowait %steal %idle
3.96 0.00 4.19 26.41 0.00 65.44
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 102.00 0.00 1330.14 0 6664
sda1 0.00 0.00 0.00 0 0
sda2 0.00 0.00 0.00 0 0
sda3 0.00 0.00 0.00 0 0
sda4 0.00 0.00 0.00 0 0
sda5 102.00 0.00 1330.14 0 6664
sda6 0.00 0.00 0.00 0 0
avg-cpu: %user %nice %system %iowait %steal %idle
3.98 0.00 3.85 29.69 0.00 62.47
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 57.40 0.00 856.00 0 4280
sda1 0.00 0.00 0.00 0 0
sda2 0.00 0.00 0.00 0 0
sda3 0.00 0.00 0.00 0 0
sda4 0.00 0.00 0.00 0 0
sda5 57.40 0.00 856.00 0 4280
sda6 0.00 0.00 0.00 0 0
avg-cpu: %user %nice %system %iowait %steal %idle
6.23 0.00 6.54 28.80 0.00 58.43
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 281.60 3249.60 3105.60 16248 15528
sda1 0.00 0.00 0.00 0 0
sda2 0.00 0.00 0.00 0 0
sda3 0.00 0.00 0.00 0 0
sda4 0.00 0.00 0.00 0 0
sda5 281.60 3249.60 3105.60 16248 15528
sda6 0.00 0.00 0.00 0 0
I also created Red Hat case #00600185 The behavior is actually not as different as I thought with sysstat 8 on Debian (the iostat % seems to be higher rather than lower, but the other behavior is still the same). The behavior still strikes me as unusual. Ahah. I looked in TFM before, but not in the right place... near the top: "The first report generated by the iostat command provides statistics concerning the time since the system was booted." You can close this. |