1. Home
  2. General
  3. How do I replace ntpd for chrony on a Bright Cluster?

How do I replace ntpd for chrony on a Bright Cluster?

The following procedure was tested on Bright 8.2 on CentOS-7u7

WARNING: Please note that an update of certain Bright packages can remove some of the changes that were done manually here. If the  packages node-installer or  node-installer-nfsroot are updated/reinstalled on the head node, then step 7 of this article has to be done again. 

1 – Disable ntpd on the head node

Run the following commands on the head node:

# systemctl disable ntpd
# systemctl stop ntpd
# cmsh
% device use master
% services
% use ntpd
% stop
% set autostart no
% set monitored no
% commit

2 – Disable ntpd on the software images

Run the following commands on the head node (this has to be done for every software image)

# chroot /cm/images/<software images>
# systemctl disable ntpd
# exit

3 – Install chrony on the head node and software images

Run the following commands on the head node:

# yum install chrony
# yum install chrony –installroot=/cm/images/<software image>
… repeat this last step for every software image

4 – Configure chrony on the head node

In the head node, edit the /etc/chrony.conf file and add the following line (replace the network for the network from which the compute nodes will access the head node)

allow 10.141.0.0/16

5 – Configure chrony on the software images

In every software image edit the /etc/chrony.conf file, comment all the lines starting with “server” and add a line which points to the IP address the compute nodes use to reach the head node, for example:

server 10.141.255.254 iburst

6 – Configure the head node and compute nodes to manage chronyd

Run the following commands on the head node:

# cmsh
% device use master
% services
% add chronyd
% set monitored yes
% set autostart yes
% commit
% start
% category use <category of the nodes>
% services
% add chronyd
% set monitored yes
% set autostart yes
% commit

7 – Configure node-installer to use chrony instead of ntpd

Run the following commands on the head node:

# yumdownloader chrony libseccomp
# rpm -ivh chrony-3.2-2.el7.x86_64.rpm libseccomp-2.3.1-3.el7.x86_64.rpm –root=/cm/node-installer

8 – Reboot nodes to apply the changes

All the compute nodes have to be rebooted so the changes in the software images will be applied.

Updated on August 20, 2020

Was this article helpful?

Related Articles

Leave a Comment