Bacula is a highly portable C application but can the administrator may still find a limited operational system or device without the need resources to install or build a backup client (e.g.: esxi).
In this case one option is to appeal to the most common service SSH to fetch the data and make a streaming straight to another Linux Bacula client with bpipe (to learn more about bpipe visit the online course).
Sshpass (e.g.: apt-get install sshpass) should be installed in the client machine running bpipe, but you could also use keys for ssh authentication instead of using password.
This is a simple example of a remote /etc backup:
Plugin = "bpipe:/mnt/fifo/etc_hfaria.tar:sshpass -p 'user_passwd' ssh -o StrictHostKeyChecking=no firstname.lastname@example.org /bin/tar -c /etc:sshpass -p 'user_passwd' ssh -o StrictHostKeyChecking=no email@example.com /bin/tar -C /tmp -xvf -"
The 4th bpipe command variable will restore this data according to what I specified, directly to the machine owner of the data (/tmp). This is what is presented and should be marked for restore:
-rwx—— 0 root root -1 2015-11-28 10:19:40 */mnt/fifo/etc_hfaria.tar