Deciding which feature (on-host agent or agentless) of NetBackup Snapshot Manager is to be used for protecting the assets
For NetBackup to discover and protect assets on a host for single file restore or filesystem/application consistency, then install the agent on the host, even if snapshots are filesystem/application consistent through provider-managed consistency.
(For Microsoft Azure cloud provider) To use Azure recovery points for the snapshots to be application consistent, refer to the following table to connect and configure the VM's in Azure cloud:
(For OCI) Block volumes created or attached while creating instances are not supported for consistent snapshots using the on-host or agentless connections.
| For Windows | For Linux |
|---|---|
No need to connect and configure the VM's |
|
The agent installs necessary plugins for performing the required operations for protecting the assets on the host.
One of the following approach can be used to install agents on their hosts that must be protected:
On-host agent
Agentless
In both the above approaches, the same plug-ins are installed on the host to perform the operations. However the difference in the above two approaches are as follows:
On-host agent | Agentless |
|---|---|
User must manually install the agent on the host and register it to the Snapshot Manager host | The agent can be installed on the host using the NetBackup Web UI, by connecting/configuring the VM. |
User must not share the Host credentials to the Snapshot Manager, as the user would install it manually on the host. | The Host/VM credentials must be stored in NetBackup credential manager, so that Snapshot Manager can connect to the host and install the agent and necessary plugins. |
Connection is permanently setup over RabbitMQ port 5671 to the host VM from the Snapshot Manager to collect and send data. | Each time when an operation (as follows) must be performed on the host, then the Snapshot Manager temporarily connects to the VM using SSH port for Linux/Windows and installs the agent:
This then pushes the plugins to performs necessary operations and uninstall itself. The data is however transferred. |
The agent once installed manually always remains on the host unless it is uninstalled, hence the name on-host agent feature. | As the agent is not always present on the host hence, the name agentless feature. |
As connectivity is established once and remains until the agent is unregistered and uninstalled. This approach is faster compared to agentless feature while performing the operations on the host. | As connectivity has to be established each time an operation has to be performed on the host, and agents/plugins would have to be installed for each connection. This approach is time consuming in comparison to on-host agent feature. |
Upgrades have to be manually performed on the on-host agent when NetBackup Snapshot Manager would be upgraded. | When NetBackup Snapshot Manager is upgraded the upgrades are automatically pushed to the host from NetBackup Snapshot Manager. |
Note:
For NetBackup to discover and protect assets on a host for single file restore or filesystem/application consistency, then install the agent on the host, even if snapshots are filesystem/application consistent through provider-managed consistency.