This article serves as an introduction to Cloud Server Snapshot Long-Term Retention. 

For more information on Snapshots, see Introduction to Cloud Server Snapshots

Content / Solution:


Many organizations have a need to retain backups for an extended period of time to meet compliance requirements, in some cases for up to 7 years. Snapshot Long-Term Retention Images is an add-on feature of Cloud Server Snapshot Service that allows users to specify that they want to keep a System Snapshot for a longer period than what is allowed under the Snapshot Service Plans (i.e. longer than 1 year).  Once this feature is enabled, CloudControl will create and store Long-Term Retention Images on a predetermined schedule as specified by the User. This feature provides a solution for Cloud Server Snapshots which is not tied to proprietary vendor formats. These images are stored using standard vSphere datastores, meaning that if the underlying technology of Cloud Server Snapshots is changed, Long-term Retention Images will not be “stuck” in a legacy vendor format.

Users can select whether to retain the images in the same Data Center, in the replicated Data Center or in both the local and replicated Data Centers where the Snapshot-enabled server resides. Users will specify how often they want a Long-Term Image to be created (Frequency) and how long (Retention Period) they want each Image to be retained.  Once enabled, CloudControl will periodically create a Long-Term Retention Image from the most recent, non-archived System Snapshot using the specified Frequency, and this image will be stored by the System for the specified Retention Period.

Users can identify whether a location has the Snapshot Long-Term Retention Images feature available on the Data Center Dashboard under Data Center Specifications. If enabled for the location, the Data Center Dashboard will show the Minimum and Maximum values for both Frequency and Retention.

Enablement May Be Temporarily Blocked

In rare situations, enabling Long-Term Retention on a Server may be temporarily disabled; if this is the case, the Data Center Dashboard will display the "Long Term Retention Enablement Blocked Reason" field, showing why enablement is blocked - for example: "Enablement is blocked due to lack of datastore capacity for Long-Term Retention Images in the Location". When Enablement is blocked, this also prevents CloudControl from attempting to create any new Long-Term Retention Images for existing Servers already enabled for this feature.

Creating Snapshot Long-Term Retention Images

In any location where the service is enabled, any Snapshot-enabled Server can also be enabled for Snapshot Long-Term Retention Images. 

When enabling this feature, the User will specify:

  • Scope: Local, Replicated, or Both - Where do you want the Long-Term Retention Images stored
  • Frequency: How often do you want the System to create a Long-Term Retention Image
    • Frequency must be between the Minimum and Maximum Frequency values for the location (inclusive)
  • Retention: How long will the System store the Long-Term Image
    • Retention must be between the Minimum and Maximum Retention values for the location (inclusive)
  • Note that Users cannot specify a different Frequency or Retention period for the Local and Replicated Locations, these must be set to the same values for both.

Once enabled, CloudControl has a background process that will take the most recent non-archived System Snapshot (Local, Replicated or Both as specified by the User) and create a Long-Term Retention Image.

In order to do this, CloudControl will:

  • Create a Snapshot Preview Server in a stopped state - similar to the User-initiated How to Create a Snapshot Preview Server from a Local Snapshot 
  • "Migrate" the Snapshot Preview Server to the datastore designated for Long Term Retention Images for that location
    • This involves a Storage vMotion of the virtual disks on the Server from the snapshot infrastructure to a production datastore designated for Long-Term Retention Images
  • Set the expiry time on the Long-Term Retention Image based on the Retention Time specified by the User.

Users can view these Long-Term Retention Images either on the Server Dashboard under the "Snapshot" section or under the "Images and Applications" view where Long-Term Images will appear along with OS Images and Client Images.

Modifying Long-Term Retention Image Scope, Frequency, and Retention

Users can modify the Long-Term Retention Images Scope (Local, Replicated or Both), Frequency, and Retention on a Snapshot Long-Term Retention Images-enabled Server however these changes will only apply going forward, any existing Long-Term Retention Images will keep their expiry times. Newly created images after the change will follow the updated Frequency and Retention periods specified. For Example: 

A User enables Snapshot Long-Term Retention Images feature on a Server on 1 March 2020 with a Frequency of 90 Days and a Retention period of 2 Years. Initial Long-Term Retention Image will be created March 1, 2020 with an expiry date of 1 March, 2022. 90 days later, on 30 May, 2020 the next Long Term image will be created and have an expiry date of 30 May 2022.

On 15 June, 2020, the User decides to change the frequency to every 45 days but leave the retention at 2 years. The System treats this change the same as enabling a server for this feature. CloudControl will take the most recent non-archived System Snapshot and immediately create a new Long-Term Retention Image on 15 June 2020 with an expiry date of 15 June 2022. 45 days later, on 30 July 2020, the next scheduled Long-Term Retention Image will be created with an expiry date of 30 July 2022. The existing images with expiry dates of 1 March 2022 and 30 May, 2022 respectively will not be modified by CloudControl, however if desired, the User can edit the expiry time of these images  (or any Client image), including the ability to remove expiry time entirely from a Client image. 

Removing Long-Term Retention enablement from a Cloud Server

Users can remove the Snapshot Long-Term Retention Images feature from the Local, Replicated, or both Data Centers, however any existing Long-Term Retention Images will not be automatically deleted until they reach their expiry time or are proactively deleted by the User.

Actions that Users can take against Long-Term Retention Images:

  1. Edit Metadata:
    1. You can edit metadata on a Long-Term Retention Image just as you can for a Client Image today (see How to Manage Client and Long-Term Retention Images). In addition, Users will be able to edit the Expiry Time of a Long-Term Retention Image (or any Client Image), including the option to remove the Expiry Time, i.e. that the Image will "never expire".
  2. Deploy a Server with Non-Guest OS Customization (see How to Deploy a Cloud Server from a Non-Guest OS Customization Image)
    1. Note that deployment could potentially be a long-running process, as these images could be as large as 30TB, the maximum size of a Snapshot in a location
  3. Delete the Long-Term Retention Image

Actions Users cannot take against Long-Term Retention Images

For technical reasons mainly related to the large size of these images, Users are prohibited from the following actions on Long-Term Retention Images:

  1. Copy Client Image to Data Center
  2. Move Client Image to Cluster
  3. Export Client Image to Data Center

Usage Charges for Long-Term Retention Images

Usage will be charged under the Long Term Image Storage Hours usage element and will be based on the cumulative size of all the disks on each Long-Term Retention Image. Usage will be visible on the Summary and Detailed Usage Reports (see Introduction to Usage Reporting)

Usage will be incurred for each Long-Term Retention image that is created based on the size of the disks on the Source Server.

For example: If a User enables Snapshot Long-Term Retention Images on a server with 3 local disks of 30 GB each for a total of 90 GB on the server. The user has requested that a Long-Term Retention Image be created every 30 days and stored for 1 year.  The System will take the most recent non-archived System Snapshot and create a Long-Term Retention Image from it. This Server Image will incur 90 Long Term Image Storage Hours per hour until either the User deletes it or it expires. If the user adds another 30 GB disk on to the server at this point, it doesn't change the billing for that Image. However, after 30 days, another the next Long Term Retention Image will be created, and this one will incur 120 Long Term Image Storage Hours per hour as long as it exists as that's the size of that Image.

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