Hi, I have Gentoo Linux dom0 and paravirtual domUs with Xen 3.4.2 all of them with `/proc/sys/xen/independent_wallclock'' set to 0 (dom0 and domUs) but domUs aren''t in sync with dom0. I''ve noticed this after a while, because I saw a recent line in a log file with the time in the future. Then I went to the dom0, set time quickly with ntpdate and started ntpd. After this I noticed that all domUs still had the same time so I waited... and waited to see the changes take effect. Nothing happened. It''s been a day since then, and I can see dom0 and domUs are all acting as if they were configured to use the independent wall clock. I was able to change the time of one of the domUs and still see it differs both from dom0 and the other domUs. I googled and searched the archives but couldn''t find a way out. It would really mean a lot to me not to have to maintain ntp in all domUs... Thanks a lot for your job! _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi, Check the hwclock on dom0, make sure this is updated not just the system time. Should fix your issues. Joseph. On 7 July 2011 23:18, Diego Molina <diegoaugustomolina@gmail.com> wrote:> Hi, I have Gentoo Linux dom0 and paravirtual domUs with Xen 3.4.2 all > of them with `/proc/sys/xen/independent_wallclock'' set to 0 (dom0 and > domUs) but domUs aren''t in sync with dom0. > I''ve noticed this after a while, because I saw a recent line in a log > file with the time in the future. Then I went to the dom0, set time > quickly with ntpdate and started ntpd. After this I noticed that all > domUs still had the same time so I waited... and waited to see the > changes take effect. Nothing happened. It''s been a day since then, and > I can see dom0 and domUs are all acting as if they were configured to > use the independent wall clock. I was able to change the time of one > of the domUs and still see it differs both from dom0 and the other > domUs. I googled and searched the archives but couldn''t find a way > out. It would really mean a lot to me not to have to maintain ntp in > all domUs... > > Thanks a lot for your job! > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >-- Kind regards, Joseph. Founder | Director Orion Virtualisation Solutions | www.orionvm.com.au | Phone: 1300 56 99 52 | Mobile: 0428 754 846 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
El 07/07/11 14:49, Joseph Glanville escribió:> Hi, > > Check the hwclock on dom0, make sure this is updated not just the system time. > Should fix your issues. > > Joseph. >Hi again, already checked the hwclock on dom0. It''s set correctly. I was suggested by Alexandre Tatut to use this config for the domU: rtc_timeoffset=0 timer_mode=1 localtime=1 Nothing different. Clock still independent. I was also suggested to use NTP in each domU, but that''s what I''m trying to avoid. Seriously, any suggestion welcome: tests are feasible at least by now (I''ve got a domU which is not in production yet but should be soon; the others had their time corrected by hand using ntpdate). -- Diego Augusto Molina diegoaugustomolina@gmail.com ES: Por favor, evite adjuntar documentos de Microsoft Office. Serán desestimados. EN: Please, avoid attaching Microsoft Office documents. They shall be discarded. LINK: http://www.gnu.org/philosophy/no-word-attachments.html _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
2011/7/7, Diego Molina <diegoaugustomolina@gmail.com>:> Hi, I have Gentoo Linux dom0 and paravirtual domUs with Xen 3.4.2 all > of them with `/proc/sys/xen/independent_wallclock'' set to 0 (dom0 and > domUs) but domUs aren''t in sync with dom0. > I''ve noticed this after a while, because I saw a recent line in a log > file with the time in the future. Then I went to the dom0, set time > quickly with ntpdate and started ntpd. After this I noticed that all > domUs still had the same time so I waited... and waited to see the > changes take effect. Nothing happened. It''s been a day since then, and > I can see dom0 and domUs are all acting as if they were configured to > use the independent wall clock. I was able to change the time of one > of the domUs and still see it differs both from dom0 and the other > domUs. I googled and searched the archives but couldn''t find a way > out. It would really mean a lot to me not to have to maintain ntp in > all domUs... > > Thanks a lot for your job! >Even stranger: 1) I Shut down one domU and created it again. Not even at start up the clock was correct. It keeps wrong. I''ve noticed that after a while of changing the system time it rolls back to the wrong state again in a consistent manner, so that all domUs end up with a similar (not equal) wrong time. One may think it may be due to a /etc/localtime (or similar) misconfig, but the drift is given within minutes, not *exact* hours (that''s an easy way to discard that option). 2) Not even ntp could keep the time correct in the domUs!!!! Ok, this is serious. Once in a while the time was correct (after a sync), then it went wrong as much as it could. 3) This morning we had to shut the whole rack down due to a general upgrade and mantainance. When I booted all machines the time was correct again everywhere! This is straaaange, and I have the impression that this can be caused by a continuous process of drifting during the dom0 uptime. Even with an obscure explanation like this it is still strange. I started to think about a hardware failure, even been a new server (about five months old) but couldn''t find anything bad with standard tools. Also, time was well kept in dom0 so that may mean hw is ok too. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
2011/7/7, Diego Molina <diegoaugustomolina@gmail.com>:> Hi, I have Gentoo Linux dom0 and paravirtual domUs with Xen 3.4.2 all > of them with `/proc/sys/xen/independent_wallclock'' set to 0 (dom0 and > domUs) but domUs aren''t in sync with dom0. > I''ve noticed this after a while, because I saw a recent line in a log > file with the time in the future. Then I went to the dom0, set time > quickly with ntpdate and started ntpd. After this I noticed that all > domUs still had the same time so I waited... and waited to see the > changes take effect. Nothing happened. It''s been a day since then, and > I can see dom0 and domUs are all acting as if they were configured to > use the independent wall clock. I was able to change the time of one > of the domUs and still see it differs both from dom0 and the other > domUs. I googled and searched the archives but couldn''t find a way > out. It would really mean a lot to me not to have to maintain ntp in > all domUs... >Hi again, it''s been about six days of uptime and I started a test from the early bootup of all the machines. The test is very simple and consists of: - Provision: all gentoo systems, 4 domUs, pv. At bootup, I run ntpdate in all machines and start ntpd in dom0 and in three domUs. The forth one is the control. Dom0 syncs against a trusty server and domUs against dom0. Periodically (each 7 days) the date in the 5 machines are checked simultaneously with `date +%Y%m%d-%H%M%S-%N''. After this I stop ntpd in one domU, wait another 7 days and process starts over. I hope this ends up showing the degradation of time in each machine. Sincerely, I hope there''s no degradation at all :) When I say I run something in more than one server (somthing like ntpdate or date) I do it "at the same time" thanks to my terminal manager, which allows me to run commands on multiple terms at the same time - First result: we have passed the first 7 days and this is the result of the "synchronous" date command: dom0: 20110719-114359-087087066 1st domU/ntp: 20110719-114352-634035597 2nd domU/ntp: 20110719-114352-591847797 3rd domU/ntp: 20110719-114352-551410325 domU: 20110719-114353-232691277 This test may be dummy and may not pass most statistics test proofs. If you can improve it, if you think it''s loss of time, pointless, please help me build a worthwhile test. Do you think domUs should sync against the foreign server? I didn''t do this because I wanted domUs to depend on dom0. If they would be independant, then it *should* be like any other machine syncing against a time server. Another notice: time doesn''t jump anymore, I''ve been seeing the logs and time keeps advancing in a clear way though not consistent (else there would be no drifts). _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users