http://bugzilla.novell.com/show_bug.cgi?id=545191 User pgnet.dev@gmail.com added comment http://bugzilla.novell.com/show_bug.cgi?id=545191#c1 Summary: ntpd sync fails/noisy with kernel-xen (clocksource = jiffies); works as expected with kernel-default (clocksource = hpet) Classification: openSUSE Product: openSUSE 11.1 Version: Final Platform: x86-64 OS/Version: openSUSE 11.1 Status: NEW Severity: Major Priority: P5 - None Component: Kernel AssignedTo: bnc-team-screening@forge.provo.novell.com ReportedBy: pgnet.dev@gmail.com QAContact: qa@suse.de Found By: --- User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9) Gecko/2008052906 Firefox/3.0 FirePHP/0.3 i've set up two identical servers -- same mobo (Asus M387A-CM), BIOS version (v1903), CPU (AMD Phenom II X4 2.6GHz), OS (opensuse 11.1), & kernel version (2.6.27.29-0.1). the difference between the 2 is that server (1) is running a Xen Dom0 kernel, and server (2) is running the default, non-Xen kernel. both machines are setup to use NTP for time services. i've identically config'd ntp, using 3 low-latency Stratum 2 servers. cat /etc/ntp.conf restrict default nomodify notrap noquery restrict 127.0.0.1 restrict 192.168.1.0 mask 255.255.255.0 notrust nomodify notrap server ntp1.stsn.net server clock.develooper.com server 192.83.249.28 driftfile /var/lib/ntp/drift/ntp.drift logfile /var/log/ntpd/ntp.log statsdir /var/log/ntpd/ filegen peerstats file peerstats type day enable filegen loopstats file loopstats type day enable filegen clockstats file clockstats type day enable i restarted ntpd on both servers at the same time, and waited 2 hours. server (2) is synced (took about 10 minutes, actually), with low jitter and offset, to stratum3; server (1) hasn't managed to make it out of stratum 16 ... (1) uname -a Linux server02 2.6.27.29-0.1-xen #1 SMP 2009-08-15 17:53:59 +0200 x86_64 x86_64 x86_64 GNU/Linux cat /sys/devices/system/clocksource/clocksource0/available_clocksource xen jiffies cat /sys/devices/system/clocksource/clocksource0/current_clocksource jiffies cat /proc/sys/xen/independent_wallclock 1 service ntp stop && sntp -P no -r us.pool.ntp.org && service ntp start && date Shutting down network time protocol daemon (NTPD) done Starting network time protocol daemon (NTPD) done Wed Oct 7 16:28:44 PDT 2009 .. .. date Wed Oct 7 18:50:21 PDT 2009 ntpq -p -c rv ... stratum=16, precision=-8, rootdelay=0.000, rootdispersion=10.485, ... remote refid st t when poll reach delay offset jitter ============================================================================== *time-sj.stsn.ne 198.60.22.240 2 u 57 64 377 27.612 -1390.8 658.318 +clock-a.develoo 204.123.2.72 2 u 15 64 377 28.280 -1478.4 652.232 +zorro.sf-bay.or 216.218.254.202 2 u 52 64 377 17.287 -1395.2 650.788 (2) uname -a Linux server03 2.6.27.29-0.1-default #1 SMP 2009-08-15 17:53:59 +0200 x86_64 x86_64 x86_64 GNU/Linux cat /sys/devices/system/clocksource/clocksource0/available_clocksource hpet acpi_pm jiffies tsc cat /sys/devices/system/clocksource/clocksource0/current_clocksource hpet service ntp stop && sntp -P no -r us.pool.ntp.org && service ntp start && date Shutting down network time protocol daemon (NTPD) done Starting network time protocol daemon (NTPD) done Wed Oct 7 16:28:46 PDT 2009 .. .. date Wed Oct 7 18:51:07 PDT 2009 ntpq -p -c rv ... stratum=3, precision=-20, rootdelay=47.377, rootdispersion=14.367, ... remote refid st t when poll reach delay offset jitter ============================================================================== *time-sj.stsn.ne 198.60.22.240 2 u 64 64 377 28.779 -4.716 2.679 +clock-b.develoo 204.123.2.72 2 u 59 64 377 26.669 -0.886 3.322 +zorro.sf-bay.or 216.218.254.202 2 u 51 64 377 16.563 -0.645 2.906 finally, i swapped the kernel-default & kernel-xen between the two machines, and saw the same/similar results. if i understand the above correctly, this says "problem with timing @ Xen kernel" to me ... this manifests as problematic for DomU localtime-dependent on Dom0 sync using xen closksource for apps (e.g. Dovecot) sensitive to noisy/incorrect/backward-moving time. Reproducible: Always Steps to Reproduce: 1. 2. 3. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.