I am receiving lots of messages like these on my xen virtual machines: Feb 17 06:57:54 XXX-vm kernel: [61138.593289] __ratelimit: 138 messages suppressed Feb 17 06:57:54 XXX-vm kernel: [61138.593289] clocksource/0: Time went backwards: ret=3b05d54bddc delta=-65371689384312 shadow=3b05d288427 offset=2c75df Feb 17 06:57:54 XXX-vm kernel: [61138.593289] __ratelimit: 133 messages suppressed Feb 17 06:57:54 XXX-vm kernel: [61138.593289] clocksource/0: Time went backwards: ret=3b188b7d968 delta=-65366666501612 shadow=3b1872eab3b offset=18978b8 Feb 17 06:57:54 XXX-vm kernel: [61138.593289] __ratelimit: 97 messages suppressed Feb 17 06:57:54 XXX-vm kernel: [61138.593289] clocksource/0: Time went backwards: ret=3b2b910bbd2 delta=-65361560402818 shadow=3b2b134cf7a offset=7dc452f Feb 17 06:57:54 XXX-vm kernel: [61138.593289] __ratelimit: 198 messages suppressed Feb 17 06:57:54 XXX-vm kernel: [61138.593289] clocksource/0: Time went backwards: ret=3b3dabe5629 delta=-65356700410155 shadow=3b39fa01ee9 offset=3b1e7453 Feb 17 06:57:54 XXX-vm kernel: [61138.593290] __ratelimit: 425 messages suppressed Feb 17 06:57:54 XXX-vm kernel: [61138.593290] clocksource/0: Time went backwards: ret=3b505b86c49 delta=-65351684410123 shadow=3b505410ae9 offset=77a3ab What do these messages indicate? Did I missed something on my setup? Oliver _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Please read this : If a domU crashes or freezes while uttering the famous lasts words ''clocksource/0: Time went backwards'', your domU is likely using the xen clocksource instead of its own clock ticks. In practice, this seems to be the cause of infrequent lockups under load (and/or problems with suspending). A workaround is to decouple the clock in the domU from the dom0: In your dom0 and domU /etc/sysctl.conf add the line: xen.independent_wallclock=1. On the dom0, edit the configuration file of the domU (e.g. /etc/xen/foobar.cfg and add (or expand) the extra-line: extra="clocksource=jiffies". These settings can be activated without rebooting the domU. After editing the configuration files, issue sysctl -p and echo "jiffies"> /sys/devices/system/clocksource/clocksource0/current_clocksource on the domU prompt. Because the clock won''t be relying on the dom0 clock anymore, you probably need to use ntp on the domU to synchronize it properly to the world. Olivier. XO Project http://xen-orchestra.com On Wed, Feb 17, 2010 at 9:05 AM, Oliver Rojo <orojo@tresmax.asia> wrote:> I am receiving lots of messages like these on my xen virtual machines: > > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] __ratelimit: 138 messages suppressed > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] clocksource/0: Time went backwards: ret=3b05d54bddc delta=-65371689384312 shadow=3b05d288427 offset=2c75df > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] __ratelimit: 133 messages suppressed > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] clocksource/0: Time went backwards: ret=3b188b7d968 delta=-65366666501612 shadow=3b1872eab3b offset=18978b8 > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] __ratelimit: 97 messages suppressed > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] clocksource/0: Time went backwards: ret=3b2b910bbd2 delta=-65361560402818 shadow=3b2b134cf7a offset=7dc452f > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] __ratelimit: 198 messages suppressed > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] clocksource/0: Time went backwards: ret=3b3dabe5629 delta=-65356700410155 shadow=3b39fa01ee9 offset=3b1e7453 > Feb 17 06:57:54 XXX-vm kernel: [61138.593290] __ratelimit: 425 messages suppressed > Feb 17 06:57:54 XXX-vm kernel: [61138.593290] clocksource/0: Time went backwards: ret=3b505b86c49 delta=-65351684410123 shadow=3b505410ae9 offset=77a3ab > > What do these messages indicate? Did I missed something on my setup? > > Oliver > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Wow that did the trick! Thanks a lot! ----- Original Message ----- From: Olivier LAMBERT [mailto:lambert.olivier@gmail.com] To: Oliver Rojo [mailto:orojo@tresmax.asia] Cc: xen-users@lists.xensource.com Sent: Wed, 17 Feb 2010 08:32:44 +0000 Subject: Re: [Xen-users] Time went backwards> Please read this : > If a domU crashes or freezes while uttering the famous lasts words > ''clocksource/0: Time went backwards'', your domU is likely using the > xen clocksource instead of its own clock ticks. In practice, this > seems to be the cause of infrequent lockups under load (and/or > problems with suspending). A workaround is to decouple the clock in > the domU from the dom0: > > In your dom0 and domU /etc/sysctl.conf add the line: > xen.independent_wallclock=1. On the dom0, edit the configuration file > of the domU (e.g. /etc/xen/foobar.cfg and add (or expand) the > extra-line: extra="clocksource=jiffies". > > These settings can be activated without rebooting the domU. After > editing the configuration files, issue sysctl -p and echo "jiffies"> > /sys/devices/system/clocksource/clocksource0/current_clocksource on > the domU prompt. > > Because the clock won''t be relying on the dom0 clock anymore, you > probably need to use ntp on the domU to synchronize it properly to the > world. > > > > Olivier. > XO Project > http://xen-orchestra.com > > On Wed, Feb 17, 2010 at 9:05 AM, Oliver Rojo <orojo@tresmax.asia> wrote: > > I am receiving lots of messages like these on my xen virtual machines: > > > > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] __ratelimit: 138 messages > suppressed > > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] clocksource/0: Time went > backwards: ret=3b05d54bddc delta=-65371689384312 shadow=3b05d288427 > offset=2c75df > > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] __ratelimit: 133 messages > suppressed > > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] clocksource/0: Time went > backwards: ret=3b188b7d968 delta=-65366666501612 shadow=3b1872eab3b > offset=18978b8 > > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] __ratelimit: 97 messages > suppressed > > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] clocksource/0: Time went > backwards: ret=3b2b910bbd2 delta=-65361560402818 shadow=3b2b134cf7a > offset=7dc452f > > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] __ratelimit: 198 messages > suppressed > > Feb 17 06:57:54 XXX-vm kernel: [61138.593289] clocksource/0: Time went > backwards: ret=3b3dabe5629 delta=-65356700410155 shadow=3b39fa01ee9 > offset=3b1e7453 > > Feb 17 06:57:54 XXX-vm kernel: [61138.593290] __ratelimit: 425 messages > suppressed > > Feb 17 06:57:54 XXX-vm kernel: [61138.593290] clocksource/0: Time went > backwards: ret=3b505b86c49 delta=-65351684410123 shadow=3b505410ae9 > offset=77a3ab > > > > What do these messages indicate? Did I missed something on my setup? > > > > Oliver > > > > _______________________________________________ > > Xen-users mailing list > > Xen-users@lists.xensource.com > > http://lists.xensource.com/xen-users > > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users