Create Backup Task
To back up VMs, you must configure a backup task to define how, where, and when to back up the VM data. A backup task can be used to process one VM or more. You can configure a backup task and start it immediately or save the task and run it later. This section will guide you through how to create backup tasks step by step.
Contents
- Before You Start
- Launch the Backup Wizard
- Backup Wizard
Before You Start
Before you start, please check if there are existing VMs. If not, please follow the steps below to add the vCenter Server or vSphere Hypervisor (ESX / ESXi) to have VMs available.
- Click Manage VMware vSphere > Add to connect to VMware vSphere.
- Fill in the server address and account information to connect to VMware vSphere.
Note: The storage space of the backup destination and the volume where the package is installed must be at least 8GB to perform a backup task.
Apart from adding VMware vSphere, you can also edit or delete the vCenter Server or vSphere Hypervisor (ESX / ESXi) in Manage VMware vSphere:
- Edit: Select the existing servers and change the account names and passwords.
- Delete: Delete the servers that are not needed. If there are protected VMs in current backup tasks, you need to delete those tasks in order to delete the servers.
Launch the Backup Wizard
You can do any of the following to launch the backup wizard:
- Go to Active Backup for Business > Virtual Machine > Virtual Machine and single select a virtual machine or press shift or ctrl and left click to select multiple virtual machines that you want to back up. Click Create Task to launch the backup wizard.
- Go to Active Backup for Business > Virtual Machine > Virtual Machine, and click Create Task to launch the backup wizard.
- Go to Active Backup for Business > Virtual Machine > Task, and click Create to launch the backup wizard.
Backup Wizard
To select backup destination and VMs:
After the backup wizard has been launched, select a shared folder in the Btrfs file system as the backup destination. Then, specify the backup task name, and select the VMs for this backup task.
Note:
If you have already selected a VM in the Virtual Machine tab, the selected VM will be automatically displayed in this step.
To configure task settings:
- Maximum quantity of concurrent backup device(s): Configure the number of concurrent backed up devices. The maximum number of backed up virtual machines is 10.
- Enable VMware Changed Block Tracking: Enable VMware Changed Block Tracking (CBT) to only transfer blocks that have changed since the last backup and greatly reduce the transferred data size.
- Enable Application-aware Backup: Perform an application-aware backup to ensure application data is consistent. Please note that this feature leverages VMware Tools and Microsoft's Volume Shadow Copy Service (VSS) to ensure the consistency of the backed up data for Linux and Windows VMs. Therefore, the latest version of VMware Tools needs to be installed, and the Windows VMs supporting VSS is required.
- Enable Data Transfer Compression: Compress the source data to reduce the transferred data size and significantly reduce the used storage space.
- Enable Data Transfer Encryption: Encrypts the transferred data to enhance data security.
- Enable source datastore usage detection: Since taking snapshot may require additional space on the host datastore, insufficient space on the datastore may cause the virtual machine to suspend automatically and lose data. By enabling this feature, the backup job will fail when the host datastore is lower than the certain percentage you have set.
- Enable backup verification: Enable backup verification to enhance backup reliability. By using Synology Virtual Machine Manager (VMM) to boot up a backed up device and shoot a video, users can make sure that the backup file can be properly executed.
- Take livevideo for … sec.: Specify the duration for your video, which will start shooting once Synology Virtual Machine Manager begins running the backup image. The video will be played at 3x speed.
- Advanced settings: Set up the script and credential for individual VMs.
- Select single virtual machine or shift + left click to multi-select virtual machines to specify the script / credential settings for VMs.
- Click Script to browse the script executed in the guest OS and specify the script processing mode.
- Required successful processing: VM backup process will stop if the script failed to be executed.
- Ignore script execution failure and continue the VM backup: VM backup process will continue even if the script failed to be executed.
- Click credential to specify the username and password for individual VM.
Note:
- By setting up the script and enabling the VM script execution, the credential of VM is required. An error message will be displayed if the credential is missing.
- VMware Tool is required to be installed to execute a pre-post script.
- For free ESXi, CBT is required to be manually enabled.
- Synology Virtual Machine Manager is required to be installed to enable backup verification.
- Data transfer compression cannot be enabled for versions below vSphere 5.1 because of VMware limitations.
To set the backup schedule:
You may set up the backup schedule based on your backup policy.
- Manual Backup: A backup task will only be performed when Backup is clicked manually. No scheduled backup will be performed.
- Scheduled Backup: Set the backup task to be performed on an hourly, daily or weekly basis. Click on the drop-down menu to check the days of the week you wish the task to be carried out.
To set the retention policy:
In this step, you can choose either one of the following retention policy to apply to the created task:
- Keep all versions: All the backed-up versions will be preserved.
- Apply the following methods:
You need to set at least one policy if you check Apply the following methods.
Keep only the latest versions means the maximum number of the recent versions you may keep. The exceeding versions will be rotated based on the Grandfather-Father-Son (GFS) retention policy or will be deleted when no other retention policy is configured.
Synology employs the Grandfather-Father-Son (GFS) retention policy. You can configure the time ranges of backup versions to be retained for the following time ranges respectively: daily, weekly, monthly, and yearly. If more than one backup version exists within a time range, only the latest one will be kept. For example, if you set a policy as Keep the latest version of the day for 1 day for the backup task which will be run every hour per day, only the version backed up at 23:00 will be kept.
Please note that every configured policy overlaps with each other. For example, if you would like to set the policy as keeping daily backup versions in the first three months, weekly backup versions in the second three months, and monthly backup versions in the third three months. Please tick the checkboxes and insert the numbers as the below picture displays.

The duration of 24 weeks includes the previous daily backup versions of 90 days, and the first weekly backup will be equal to the seventh daily backup. The duration of 9 months also includes the previous weekly backup versions of 24 weeks and daily backup versions of 90 days, and the first monthly backup will be equal to the fourth weekly backup.

To configure privilege settings:
Privilege settings are configurable when creating a backup task. To ensure that only eligible users can have access to restore backed-up files and versions of the backup task, privilege settings can be configured during task creation. You can always edit the task to change the privilege settings.
Check the user/group that can browse and restore backed-up versions of the task.
Administrators group/users are default eligible to restore the backup task.
To apply settings and back up the task:
After configuring all the backup settings, a backup summary will be displayed. Please follow the instructions below to finalize the backup after confirming your settings:
- Click Apply to create the backup task and a pop-up window will appear.
- Click Yes if you would like to run the backup immediately, or you may click Backup on the task list if you want to run the task afterward.