Performing time synchronization

The Time Synchronization page enables you to synchronize the internal clock of an appliance or virtual machine with a Network Time Protocol (NTP) server on your network or on the Internet or use VMware Tools time synchronization. It configures time synchronization across all the machines in a cluster. Though you can synchronize the time using the command line, see Configuring the NTP client at the command line, the preferred way is to configure through the UI.

An accurate clock is important for the operation of BMC Discovery. For example, you need to ensure that scheduled discovery runs occur at the correct time, or reconcile discovery access timestamps between multiple machines.

When the NTP daemon starts, it performs an initial synchronization. The initial synchronization can be cancelled. Thereafter, the NTP daemon maintains the correct time with regular checks

Viewing the Time Synchronization page

1. From the main menu, click the Administration icon.  
   The Administration page opens.  
2. In the Appliance section, click Time Synchronization.
   

Fields and links

• Status—Displays the status of the time synchronization. It displays No Time Synchronization when both Network Time Protocol and VMware Time Sync are disabled. When you enable VMware Time Sync, the status changes to Using VMware Time Sync. When you enable Network Time Protocol, the status changes to Using Network Time Protocol. An additional message, Time Synchronization in progress, and an option to cancel synchronization, are displayed when time is first being synchronized using NTP.
• Network Time Protocol—Displays whether the NTP time synchronization is currently enabled or disabled.
• NTP Servers—Displays the list of NTP servers configured for time synchronization.

• VMware Time Sync—Displays whether the VMware time synchronization is currently enabled or disabled. When Network Time Protocol is enabled, VMware Time Sync is disabled and this field becomes noneditable. The warning message is displayed as VMware Time Sync will be disabled when NTP is enabled. When Network Time Protocol is disabled, you can optionally re-enable VMware Time Sync.

  It is recommended that you use NTP instead of VMware Tools time synchronization as NTP provides more precise timekeeping on virtual machines. This is explained in VMware's timekeeping best practices for Linux based Virtual Machines which can be found here under the heading VMware Tools time synchronization configuration.

Actions

• Restart NTPD—Select to restart the NTP daemon. The NTP daemon performs the synchronization of the internal time with NTP servers. This option is not displayed when Network Time Protocol is disabled.
• Apply—Select to update the configuration without closing the current page. The respective messages indicating configuration updates are displayed.
• Cancel—Select to cancel changes that have not been applied and navigate back to the Administration page.

To synchronize the time

From the Time Synchronization page, you can synchronize the time of an appliance with the NTP server or across cluster members.

1. If the time is not already synchronized, Status displays No Time Synchronization. To synchronize using VMware time sync, enable VMware Time Sync. To synchronize using NTP, enable Network Time Protocol.
2. Enter the details of the NTP server or servers you want to use.
   You can toggle the server text view between the plain text view and pill view. In the pill view, as you enter text, the UI formats it as a pill (a discrete editable unit) when you enter a space or a comma. According to the text entered, the pill is formatted to represent one of the previous types or presented as invalid. By default, the list is displayed in the pill view.
   • To edit a pill, click the pill body and edit the text.
   • To delete a pill, click the X icon to the right of the pill, or click to edit and delete all of the text.
   • To view the unformatted source text, click the source toggle switch. The source view is useful for copying to a text editor or spreadsheet. Click the source toggle switch again to see the formatted pill view.
   Underneath the entry field is a filter box. Enter text in the filter box to only show matching pills.
3. Select Apply.
   An option to cancel synchronization is displayed when time is being synchronized using NTP. You can either cancel or continue with the synchronization. When time is synchronized, Status is displayed as Using Network Time Protocol.
4. If you enable Network Time Protocol when VMware Time Sync is enabled, the confirmation message is displayed as Enabling NTP will disable VMware Time Sync on any VMware Virtual Machines in the cluster. Are you sure you want to do this?. Click OK to apply the changes.