From 4b98565835b62368dee3dd694583ef6a05dfadf4 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Fabian=20Gr=C3=BCnbichler?= Date: Fri, 7 Oct 2016 15:28:31 +0200 Subject: [PATCH] sysadmin: add section about NTP configuration based on wiki article Configuration_of_Time_Syncronization_(NTP) --- Makefile | 3 ++- sysadmin.adoc | 2 ++ system-timesync.adoc | 44 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 48 insertions(+), 1 deletion(-) create mode 100644 system-timesync.adoc diff --git a/Makefile b/Makefile index 67a2b79..6125210 100644 --- a/Makefile +++ b/Makefile @@ -113,7 +113,8 @@ SYSADMIN_PARTS= \ system-software-updates \ pve-disk-health-monitoring \ local-lvm \ - local-zfs + local-zfs \ + system-timesync SYSADMIN_SOURCES= \ $(addsuffix .adoc, ${SYSADMIN_PARTS}) \ diff --git a/sysadmin.adoc b/sysadmin.adoc index d48403c..8671764 100644 --- a/sysadmin.adoc +++ b/sysadmin.adoc @@ -59,6 +59,8 @@ include::system-software-updates.adoc[] include::pve-network.adoc[] +include::system-timesync.adoc[] + include::pve-disk-health-monitoring.adoc[] include::local-lvm.adoc[] diff --git a/system-timesync.adoc b/system-timesync.adoc new file mode 100644 index 0000000..6e752a4 --- /dev/null +++ b/system-timesync.adoc @@ -0,0 +1,44 @@ +Time Synchronization +-------------------- +include::attributes.txt[] + +The {pve} cluster stack itself relies heavily on the fact that all +the nodes have precisely synchronized time. Some other components, +like Ceph, also refuse to work properly if the local time on nodes is +not in sync. + +Time synchronization between nodes can be achieved with the ``Network +Time Protocol'' (`NTP`). {pve} uses `systemd-timesyncd` as NTP client +by default, preconfigured to use a set of public servers. This setup +works out of the box in most cases. + + +Using Custom NTP Servers +~~~~~~~~~~~~~~~~~~~~~~~~ + +In some cases, it might be desired to not use the default NTP +servers. For example, if your {pve} nodes do not have access to the +public internet (e.g., because of restrictive firewall rules), you +need to setup local NTP servers and tell `systemd-timesyncd` to use +them: + +.File `/etc/systemd/timesyncd.conf` +---- +[Time] +Servers=ntp1.example.com ntp2.example.com ntp3.example.com ntp4.example.com +---- + +After restarting the synchronization service (`systemctl restart +systemd-timesyncd`) you should verify that your newly configured NTP +servers are used by checking the journal (`journalctl --since -1h -u +systemd-timesyncd`): + +---- +... +Oct 07 14:58:36 node1 systemd[1]: Stopping Network Time Synchronization... +Oct 07 14:58:36 node1 systemd[1]: Starting Network Time Synchronization... +Oct 07 14:58:36 node1 systemd[1]: Started Network Time Synchronization. +Oct 07 14:58:36 node1 systemd-timesyncd[13514]: Using NTP server 10.0.0.1:123 (ntp1.example.com). +Oct 07 14:58:36 nora systemd-timesyncd[13514]: interval/delta/delay/jitter/drift 64s/-0.002s/0.020s/0.000s/-31ppm +... +---- -- 2.39.2