From fdb010e56b19cd0efb7866fb3d0cc16b008ea3a7 Mon Sep 17 00:00:00 2001 From: Sam Yaple Date: Thu, 5 Nov 2015 09:10:47 +0000 Subject: [PATCH] Add additional ntp information around ceph Mention `chrony` since thats what docs.openstack.org recommends for WAN connections. It does do better than ntpd Change-Id: I28caade26492294bf12b092ff949003c7bf0bb8e --- doc/quickstart.rst | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/doc/quickstart.rst b/doc/quickstart.rst index 0eedcc569b..1eac54c59c 100644 --- a/doc/quickstart.rst +++ b/doc/quickstart.rst @@ -126,13 +126,17 @@ To install these clients use: pip install -U python-openstackclient -OpenStack uses healthcheck timers which run off wall-clock time rather then -starting a timer and expiring the timer, encoding the expiration in the message -contents. In some cases, this timer interval can be on the order of 60 -seconds. For OpenStack to operate correctly with these tight health-check -timer intervals, the Kolla community highly recommends running the ntpd -service on all deployment targets. To install, start, and enable ntp -execute the following: +OpenStack, RabbitMQ, and Ceph require all hosts to have matching times to ensure +proper message delivery. In the case of Ceph, it will complain if the hosts +differ by more than 0.05 seconds. Some OpenStack services have timers as low as +2 seconds by default. For these reasons it is highly recommended to setup an NTP +service of some kind. While `ntpd` will achieve more accurate time for the +deployment if the NTP servers are running in the local deployment environment, +`chrony `_ is more accurate when syncing the time +across a WAN connection. When running Ceph it is recommended to setup `ntpd` to +sync time locally due to the tight time constraints. + +To install, start, and enable ntp on CentOS execute the following: :: @@ -141,8 +145,11 @@ execute the following: systemctl enable ntpd systemctl start ntpd - # Ubuntu - sudo apt-get install ntp +To install and start on Debian based systems execute the following: + +:: + + apt-get install ntp Libvirt is started by default on many operating systems. Please disable libvirt on any machines that will be deployment targets. Only one copy of libvirt may