Description of problem: "iostat -p" command doesn't work well with interval and count parameter. For example, I try "iostat -p sda 1 3", which is with 1 second interval and 3 counts. It works well to show proper data for the first count. But in the last two count, it shows all 0 data. Version-Release number of selected component (if applicable): sysstat-7.0.0-3.el5 How reproducible: Always. Steps to Reproduce: 1. iostat -p sda 1 3 Actual results: [root@lhc ~]# iostat -p sda 1 3 Linux 2.6.18-8.el5 (lhc) 2010年05月07日 avg-cpu: %user %nice %system %iowait %steal %idle 3.94 0.86 17.88 4.12 0.00 73.20 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn sda 12.60 309.84 80.87 1544009 402982 sda2 22.67 309.24 80.85 1541021 402888 sda1 0.27 0.52 0.02 2612 94 avg-cpu: %user %nice %system %iowait %steal %idle 7.00 0.00 6.00 0.00 0.00 87.00 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn sda 0.00 0.00 0.00 0 0 sda2 0.00 0.00 0.00 0 0 sda1 0.00 0.00 0.00 0 0 avg-cpu: %user %nice %system %iowait %steal %idle 7.00 0.00 6.00 0.00 0.00 87.00 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn sda 0.00 0.00 0.00 0 0 sda2 0.00 0.00 0.00 0 0 sda1 0.00 0.00 0.00 0 0 [root@lhc ~]# Expected results: It should work well for every count.
[root@lhc ~]# uname -a Linux lhc 2.6.18-8.el5 #1 SMP Fri Jan 26 14:15:21 EST 2007 i686 i686 i386 GNU/Linux [root@lhc ~]# [root@lhc ~]# rpm -qf `which iostat` sysstat-7.0.0-3.el5 [root@lhc ~]#
Any update?
Hello, this behaviour can be ok, if there is not big r/w activity. Please what is the iostat -p sda 1 3 output if you run some dd process in parallel (e.g. dd of=/tmp/delete_me if=/dev/zero bs=1M count=1000 ) ?
Thanks very much! Yes, it works well if dd option. May this bug be closed?
Thanks, I'm closing this bug.