Date: Thu, 06 Feb 2020 20:59:09 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 243946] mdconfig -d causes iostat glitch Message-ID: <bug-243946-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=243946 Bug ID: 243946 Summary: mdconfig -d causes iostat glitch Product: Base System Version: 12.1-RELEASE Hardware: amd64 OS: Any Status: New Severity: Affects Only Me Priority: --- Component: bin Assignee: bugs@FreeBSD.org Reporter: jfc@mit.edu iostat glitched when I used mdconfig -d: tty nvd0 da0 da1 cpu tin tout KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s us ni sy in id 0 0 116.07 99 11.22 95.51 379 35.32 95.36 381 35.47 0 0 5 0 95 2 25 114.79 91 10.23 110.73 395 42.69 111.10 390 42.28 0 0 1 0 99 1 6 117.03 125 14.27 0.00 1841192139503780665 3460.45 0.00 1841192139503796095 14.38 0 0 1 0 99 2 7 119.17 96 11.21 0.00 0 0.00 0.00 0 0.00 0 0 0 0 100 I was copying files off an ISO image using mdconfig to create a special device to mount as a cd9660 filesystem. The extremely high tps in the above iostat output happened during the interval when the device was destroyed. This particular iostat was invoked as "iostat nvd0 da0 da1 10". da0 and da1 are mirrored drives in a ZFS pool so the true I/O counts should be very similar. Based on another iostat invocation without an explicit device list, md0 comes before da0 in whatever order iostat uses. My guess is destroying md0 changed indices into the device statistics table. Iostat tried to subtract "this tick's count for index 1 = da0" from "last tick's count for index 1 = md0" or something along those lines. -- You are receiving this mail because: You are the assignee for the bug.home | help
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