How to update the NTP server IP Address in VMware Cloud Foundation 2.2.x and 2.3.x

Products

• VMware Cloud Foundation

Issue/Introduction

This article provides steps on how to update the NTP server IP Address in VMware Cloud Foundation 2.2.X and 2.3.X.

Environment

VMware Cloud Foundation 2.2.x
VMware Cloud Foundation 2.3.x

Resolution

Update the /etc/ntp.conf file located on both SDDC Manager Controller VM and SDDC Manager Utility
 VM with the new NTP server IP address

 

1. ssh to the SDDC Manager Controller VM as the root user.
2. Run the following command to backup the /etc/ntp.conf file 

cp -p /etc/ntp.conf /etc/ntp_bak.conf

3. Open the /etc/ntp.conf file  with a text editor.
4. Replace the old NTP Server IP Address entry "Ex: 10.80.24.24" with the new one "Ex:10.113.60.176". 
5. Run the following command to restart the NTP service.

systemctl restart ntpd

6. Run the following command to check NTP reach number and to confirm that the new NTP server "Ex:10.113.60.176". is reachable and working as expected.

ntpq -p

Note: You should see output similar to the following:

     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*10.113.60.176   10.188.9.1       2 u   37   64  177   33.631   16.227   9.354

Note:  If the reach value is 0, this indicates a problem communicating with the configured NTP server and warrants further investigation.

7. Perform steps 2 to 6 on the SDDC Manager Utility VM.

 

 

Update the evosddcbringupinventory.ntpconfig table in Cassandra with the new NTP server IP address
 

1. ssh to the SDDC Manager Controller VM as the root user.
2. Run the following command on the SDDC Manager Controller VM to backup the Cassandra database.

/opt/vmware/sddc-support/sos --cassandra-backup

3. Run the following command  to examine the NTP sever IP address entries in the  ntpconfig table.

/opt/vmware/cassandra/apache-cassandra-2.2.4/bin/cqlsh -e "select id,servers from evosddcbringupinventory.ntpconfig"

 

Note: You will see output similar to the following:

 

 id                                   | servers
--------------------------------------+--------------------
 4f223150-17d3-11e9-961b-17401e604726 | ["192.168.100.40"]
 0b78db90-14ca-11e9-961b-17401e604726 |  ["10.113.60.176"]

Note: Make a note of the id value corresponding to the external NTP server IP address as it will be used in the next step.

4. Issue a command similar to the following to update the ntpconfig table with the new NTP server IP address .

/opt/vmware/cassandra/apache-cassandra-2.2.4/bin/cqlsh -e "update evosddcbringupinventory.ntpconfig set servers='[\"10.113.70.234\"]' where id=0b78db90-14ca-11e9-961b-17401e604726"

5. Run the command from step 5 again to validate that the new NTP server IP Address has been updated appropriately.

/opt/vmware/cassandra/apache-cassandra-2.2.4/bin/cqlsh -e "select id,servers from evosddcbringupinventory.ntpconfig"
 

Note: You will see output similar to the following:

 

 id                                   | servers
--------------------------------------+--------------------
 4f223150-17d3-11e9-961b-17401e604726 | ["192.168.100.40"]
 0b78db90-14ca-11e9-961b-17401e604726 |  ["10.113.70.234"]

Additional Information

Impact/Risks:
The Resolution steps can cause irreparable damage to the Cassandra database if not done correctly.

Notes:

• Take backups outside of SDDC if possible.
• Take snapshots of the SDDC Manager Controller VM.
• Run the following command on the SDDC Manager Controller VM to backup the Cassandra database.

/opt/vmware/sddc-support/sos --cassandra-backup