.. _video-cards:

Multiple Video Cards Usage
========================================


Should you have several video cards installed on a physical server, you can create additional ``findface-extraction-api-gpu`` or ``findface-video-worker-gpu`` instances and distribute them across the video cards, one instance per card.  

.. rubric:: In this section:

.. contents::
   :local:


Allocate ``findface-video-worker-gpu`` to Additional Video Card
-----------------------------------------------------------------------------

To create an additional ``findface-video-worker-gpu`` instance and allocate it to a different video card, do the following:
 

#. Display the ``findface-video-worker-gpu`` primary service status by executing:

   .. code::

      sudo systemctl status findface-video-worker-gpu.service
      
#. Find the full path to the service in the line ``Loaded: loaded (/lib/systemd/system/findface-video-worker-gpu.service; enabled; vendor preset: enabled``. It is ``findface-video-worker-gpu.service`` in our example (name may vary). Create a copy of the service under a new name. 

   .. code::

      sudo cp /lib/systemd/system/findface-video-worker-gpu.service /lib/systemd/system/findface-video-worker-gpu2.service`

#. In the same manner, create a copy of the primary service configuration file under a new name.

   .. code::

      sudo cp /etc/findface-video-worker-gpu.ini /etc/findface-video-worker-gpu2.ini

#. Open the just created configuration file and actualize the video card number to use.

   .. code::

      sudo vim /etc/findface-video-worker-gpu2.ini

      ## cuda device number
      device_number = 1

#. Open the new service and actualize the configuration file to use by specifying the just created one. 

   .. code::

      sudo vim /lib/systemd/system/findface-video-worker-gpu2.service

      ExecStart=/usr/bin/findface-video-worker-gpu --config /etc/findface-video-worker-gpu2.ini

#. Reload the ``systemd`` daemon to apply the changes. 
 
   .. code::

      sudo systemctl daemon-reload 

#. Enable the new service autostart.

   .. code::

      sudo systemctl enable findface-video-worker-gpu2.service

      Created symlink from /etc/systemd/system/multi-user.target.wants/findface-video-worker-gpu2.service to /lib/systemd/system/findface-video-worker-gpu2.service

#. Launch the new service. 

   .. code::

      sudo systemctl start findface-video-worker-gpu2.service

#. Check the both ``findface-video-worker-gpu`` services status.

   .. code::

      sudo systemctl status findface-video-worker-* | grep -i 'Active:' -B 3 

      ● findface-video-worker-gpu2.service - findface-video-worker-gpu daemon
        Loaded: loaded (/lib/systemd/system/findface-video-worker-gpu2.service; enabled; vendor preset: enabled)
        Active: active (running) since Thu 2019-07-18 10:32:02 MSK; 1min 11s ago

      ...

      ● findface-video-worker-gpu.service - findface-video-worker-gpu daemon
        Loaded: loaded (/lib/systemd/system/findface-video-worker-gpu.service; enabled; vendor preset: enabled)
        Active: active (running) since Mon 2019-07-15 15:18:33 MSK; 2 days ago