[Sysadmins] Q: xen и openntpd -- проблемы синхронизации

[Михаил Якушин]

Aleksey Avdeev пишет:
> Приветствую.
> 
>   На 2x ядерной системе на Arima NM46 (nVidia nForce Professional 3600
> MCP (MCP55-Pro),
> <http://www.arima.com.tw/server/Product/ViewProduct.asp?View=NM46X>)
> ловлю проблемы с синхронизацией openntpd. Выглядит это так:
> 
> 1. Когда время рассинхронизировано сильно -- вижу тенденцию к достаточно
> равномерной синхронизации:
> 
> fgrep 'ntpd[' /var/log/messages
> 
> Nov 29 14:15:22 srantal ntpd[15008]: adjusting local clock by 43.819271s
> Nov 29 14:19:40 srantal ntpd[15008]: adjusting local clock by 43.759462s
> Nov 29 14:23:52 srantal ntpd[15008]: adjusting local clock by 43.530141s
> Nov 29 14:28:13 srantal ntpd[15008]: adjusting local clock by 43.448431s
> Nov 29 14:30:23 srantal ntpd[15008]: adjusting local clock by 43.296642s
> Nov 29 14:34:45 srantal ntpd[15008]: adjusting local clock by 43.188725s
> Nov 29 14:39:05 srantal ntpd[15008]: adjusting local clock by 43.101725s
> Nov 29 14:43:24 srantal ntpd[15008]: adjusting local clock by 43.031067s
> Nov 29 14:49:43 srantal ntpd[15008]: adjusting local clock by 42.971676s
> Nov 29 14:53:53 srantal ntpd[15008]: adjusting local clock by 42.828613s
> Nov 29 14:58:10 srantal ntpd[15008]: adjusting local clock by 42.699277s
> Nov 29 15:02:26 srantal ntpd[15008]: adjusting local clock by 42.517511s
> Nov 29 15:06:44 srantal ntpd[15008]: adjusting local clock by 42.410233s
> Nov 29 15:10:56 srantal ntpd[15008]: adjusting local clock by 42.252679s
> Nov 29 15:15:14 srantal ntpd[15008]: adjusting local clock by 42.074434s
> ...
> Nov 30 13:14:22 srantal ntpd[15008]: adjusting local clock by 2.762163s
> Nov 30 13:18:39 srantal ntpd[15008]: adjusting local clock by 2.666824s
> Nov 30 13:24:11 srantal ntpd[15008]: adjusting local clock by 2.509053s
> Nov 30 13:28:29 srantal ntpd[15008]: adjusting local clock by 2.431769s
> Nov 30 13:32:42 srantal ntpd[15008]: adjusting local clock by 2.261951s
> Nov 30 13:37:04 srantal ntpd[15008]: adjusting local clock by 2.063862s
> Nov 30 13:41:20 srantal ntpd[15008]: adjusting local clock by 1.974392s
> Nov 30 13:45:51 srantal ntpd[15008]: adjusting local clock by 1.893403s
> Nov 30 13:50:11 srantal ntpd[15008]: adjusting local clock by 1.791662s
> Nov 30 13:54:30 srantal ntpd[15008]: adjusting local clock by 1.601143s
> Nov 30 13:58:43 srantal ntpd[15008]: adjusting local clock by 1.452669s
> Nov 30 14:02:55 srantal ntpd[15008]: adjusting local clock by 1.366058s
> Nov 30 14:07:19 srantal ntpd[15008]: adjusting local clock by 1.227879s
> Nov 30 14:11:29 srantal ntpd[15008]: adjusting local clock by 1.068625s
> 
> 2. Около 0 начинаются колебания, сначала достаточно слабые, но растущие
> до амплитуды примерно в 2 минуты:
> 
> Nov 30 14:15:43 srantal ntpd[15008]: adjusting local clock by 0.973161s
> Nov 30 14:19:59 srantal ntpd[15008]: adjusting local clock by 0.818756s
> Nov 30 14:26:08 srantal ntpd[15008]: adjusting local clock by 0.667731s
> Nov 30 14:31:23 srantal ntpd[15008]: adjusting local clock by 0.403073s
> Nov 30 14:36:04 srantal ntpd[15008]: adjusting local clock by 0.334943s
> Nov 30 14:40:18 srantal ntpd[15008]: adjusting local clock by 0.267176s
> Nov 30 18:39:02 srantal ntpd[15008]: adjusting local clock by -0.144020s
> Nov 30 18:55:10 srantal ntpd[15008]: adjusting local clock by -0.263865s
> Nov 30 19:00:20 srantal ntpd[15008]: adjusting local clock by -0.318400s
> Nov 30 19:04:38 srantal ntpd[15008]: adjusting local clock by -0.239041s
> Nov 30 19:48:24 srantal ntpd[15008]: adjusting local clock by 0.952979s
> Nov 30 19:56:35 srantal ntpd[15008]: adjusting local clock by 2.629649s
> Nov 30 20:00:48 srantal ntpd[15008]: adjusting local clock by 2.768256s
> Nov 30 20:03:51 srantal ntpd[15008]: adjusting local clock by 2.024156s
> Nov 30 20:08:10 srantal ntpd[15008]: adjusting local clock by -0.237597s
> Nov 30 20:16:01 srantal ntpd[15008]: adjusting local clock by -5.318358s
> Nov 30 20:20:47 srantal ntpd[15008]: adjusting local clock by -8.443175s
> Nov 30 20:25:03 srantal ntpd[15008]: adjusting local clock by -8.818382s
> Nov 30 20:31:20 srantal ntpd[15008]: adjusting local clock by -0.793047s
> Nov 30 20:35:39 srantal ntpd[15008]: adjusting local clock by 5.184628s
> Nov 30 20:39:57 srantal ntpd[15008]: adjusting local clock by 9.944269s
> Nov 30 20:44:10 srantal ntpd[15008]: adjusting local clock by 12.579240s
> Nov 30 20:48:25 srantal ntpd[15008]: adjusting local clock by 10.544748s
> Nov 30 20:54:00 srantal ntpd[15008]: adjusting local clock by -3.193970s
> Nov 30 20:58:26 srantal ntpd[15008]: adjusting local clock by -11.415809s
> Nov 30 21:02:46 srantal ntpd[15008]: adjusting local clock by -23.495780s
> Nov 30 21:07:07 srantal ntpd[15008]: adjusting local clock by -26.726273s
> Nov 30 21:11:21 srantal ntpd[15008]: adjusting local clock by -12.636701s
> Nov 30 21:15:33 srantal ntpd[15008]: adjusting local clock by 4.365099s
> Nov 30 21:19:55 srantal ntpd[15008]: adjusting local clock by 23.205746s
> Nov 30 21:22:04 srantal ntpd[15008]: adjusting local clock by 49.300694s
> Nov 30 21:26:35 srantal ntpd[15008]: adjusting local clock by 57.927283s
> Nov 30 21:31:05 srantal ntpd[15008]: adjusting local clock by 25.215511s
> Nov 30 21:35:28 srantal ntpd[15008]: adjusting local clock by 2.840327s
> Nov 30 21:39:58 srantal ntpd[15008]: adjusting local clock by -20.529180s
> Nov 30 21:44:23 srantal ntpd[15008]: adjusting local clock by -42.731609s
> Nov 30 21:48:43 srantal ntpd[15008]: adjusting local clock by -52.143453s
> Nov 30 21:53:05 srantal ntpd[15008]: adjusting local clock by -33.241482s
> Nov 30 21:57:18 srantal ntpd[15008]: adjusting local clock by -3.651981s
> Nov 30 22:01:30 srantal ntpd[15008]: adjusting local clock by 13.300128s
> Nov 30 22:05:40 srantal ntpd[15008]: adjusting local clock by 32.516868s
> Nov 30 22:09:59 srantal ntpd[15008]: adjusting local clock by 52.212004s
> Nov 30 22:14:20 srantal ntpd[15008]: adjusting local clock by 55.244622s
> Nov 30 22:18:51 srantal ntpd[15008]: adjusting local clock by 39.178210s
> Nov 30 22:23:15 srantal ntpd[15008]: adjusting local clock by 11.682577s
> Nov 30 22:27:42 srantal ntpd[15008]: adjusting local clock by -12.288741s
> Nov 30 22:32:03 srantal ntpd[15008]: adjusting local clock by -48.962899s
> Nov 30 22:36:23 srantal ntpd[15008]: adjusting local clock by -55.909022s
> Nov 30 22:40:38 srantal ntpd[15008]: adjusting local clock by -44.939905s
> Nov 30 22:44:53 srantal ntpd[15008]: adjusting local clock by -15.393383s
> Nov 30 22:49:15 srantal ntpd[15008]: adjusting local clock by 10.152480s
> Nov 30 22:53:30 srantal ntpd[15008]: adjusting local clock by 25.758460s
> Nov 30 22:57:47 srantal ntpd[15008]: adjusting local clock by 55.076543s
> Nov 30 23:02:10 srantal ntpd[15008]: adjusting local clock by 60.276839s
> Nov 30 23:06:34 srantal ntpd[15008]: adjusting local clock by 47.081275s
> Nov 30 23:11:03 srantal ntpd[15008]: adjusting local clock by 16.630958s
> 
>   В дальнейщем -- так и колеблится...
> 
> PS: По хорактеру изменений, весьма похоже что система в какой-то
> резонанс попадает (наложились несколько близких таймаутов).
Это известная проблема xen. Я думаю стоит проверить в 3.1.2. Если и там
то ждём 3.2 там должны исправить.
Рекомендую чтобы dom 0 видел все ядра. Так оно точнее работает.