Cisco Unified Communications Manager (CallManager)

Unified Communications VMware Snapshot Verification

Unified Communications VMware Snapshot Verification

Document ID: 116459

Updated: Sep 06, 2013

Contributed by John-Paul Lum Hee and Thomas Runyan, Cisco TAC Engineers.



This document describes how to check for snapshots in vSphere Client for Cisco Unified Communications (UC) applications.



Cisco recommends that you have knowledge of Virtual Machine-ware (VMware) and vSphere Client. Access to the VMware VCenter via the vSphere Client is also required.

Components Used

This document is not restricted to specific software and hardware versions. 

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Background Information

VMware snapshots are not supported in UC applications. Snapshots cause all types of latency and voice-quality issues. They also cause disk-drive space issues, CPU spikes, and memory utilization issues in UC applications.

When you troubleshoot any voice-quality or CPU/memory issues on a UC application that is supported on a VMware platform, the first thing to check is the presence of snapshots on the system. 

Check for Snapshots in vSphere Client for UC Applications

Log into vSphere Client, and select the Virtual Machine (VM) that supports the UC application. Click the Snapshot Manager icon (circled in red in the next image):

A VM that does not run snapshots shows the You are here field under the VM hostname.

Here is an example of a VM that does not run snapshots:

If snapshots are present, the You are here field appears along with the available snapshots. The snapshots appear either above or underneath the VM hostname.

Here is an example of a VM that has snapshots:


Note: For more information about why VMware snapshots are not supported, reference the Cisco Unified Communications VMware Requirements article.

You can delete snapshots without any effects to the production network, and the hosts and VMs do not need to be rebooted. Keep in mind that snapshot deletions can take up to three hours, depending on the size of the snapshot.

Note: It is recommended that you alert the Administrator that snapshots are not supported, and have the Administrator remove the snapshots from the VM that supports the UC Application.

Note: The progress of the snapshot deletion might jump to 95% immediately, and remain there for an extended period of time. This might make you think that it is stuck or hung. However, this is normal, and the task eventually completes successfully.

Alternative Procedure to Verify Snapshots on a VM

Complete these steps for an alternative to the previously-mentioned procedure:

  1. Verify the Datastore that is used by the VM. This information is on the Summary page of the VM.
  2. Navigate to Home > Inventory > Datastore and Datastore Clusters, and right-click the appropriate Datastore.
  3. Select Browse Datastore, and search for files that have the word snapshot in the title, and the delimiter .vmsn  (virtual machine snapshot).

    If you are unsure about which datastore to check, locate the VM in question, select the VM, and display the Summary page. On the Summary page, below Storage, right-click the Datastore, and select Browse Datastore.

  4. A file with snapshot in the title, as shown in the next image, indicates that a snapshot is created for this VM.

Updated: Sep 06, 2013
Document ID: 116459