Cisco HyperFlex – Change NTP Server After Deployment

Info

Recently I was in the process of deploying a HyperFlex cluster and one of the NTP servers came back as invalid due to a missing firewall rule on the network. I wanted to proceed as I still had one valid NTP server but I wasn’t sure how difficult it would be to reconfigure NTP after the HyperFlex installation. Luckily it’s pretty easy and this page can walk you through the process.

Change the NTP Server on the HyperFlex Storage Controller Nodes

The first step is to use stcli to change the NTP server(s) on the HyperFlex Storage Controller nodes. This can be done on any storage controller node and will automatically replicate to all other nodes.

• ssh to a storage controller node
• Issue the following command to list the current NTP server(s)

stcli services ntp show

• Issue the following command to add a new NTP server

stcli services ntp add –ntp 10.1.5.20

• Issue the following command to delete an NTP server (if needed)

stcli services ntp remove –ntp 10.2.5.21

• Run the show command again to verify that NTP is now configured properly.

stcli services ntp show

Change the NTP Server on the ESXi Hosts (don’t skip this step)

When you deploy a HyperFlex cluster the installer also stamps the NTP servers on each of the ESXi hosts in the HyperFlex cluster. It’s important to also reconfigure these hosts when making changes to NTP.

1. Login to the vCenter web interface
2. Go to Hosts and Clusters
3. Click on your Host
4. Select the Configure heading
5. Click Time Configuration
6. Click Edit… and update the NTP servers

References

Cisco Documentation