Failed to load module [veeamsnap] (express version)

Please note that for Veeam Agent for Linux 2.0.0.400 packages with pre-compiled modules are available. This instruction is only for cases when you need to use dkms managed veeamsnap module.

When running a backup job in Veeam Agent for Linux, the job fails with this error message:
 

Failed to load module [veeamsnap] with parameters [zerosnapdata=1 debuglogging=0]

The veeamsnap module has not been built and installed.

The veeamsnap is a DKMS module. DKMS modules have 4 states:

• not in tree;
• added;
• built;
• installed.

In general, the mentioned error message means that the veeamsnap module hasn't been installed. You can check its status by running the following command:

dkms status

If the output contains a line like veeamsnap added, this message means that the module has been added, but hasn't been built and hasn't been installed. In the most cases, this status means that your OS does not have the corresponding kernel-devel and kernel-headers for the current kernel. When the missing packages are installed, you can re-install Veeam Agent for Linux in order to execute the DKMS hooks which will rebuild and install veeamsnap. Alternatively, you can rebuild veeamsnap manually by executing the following commands:

dkms remove -m veeamsnap -v 1.0.0.944 --all
dkms build -m veeamsnap -v 1.0.0.944
dkms install -m veeamsnap -v 1.0.0.944

There is an extended version of this article here. It contains detailed explanations and examples applicable to different Linux distributions.