Optional: Reconfigure volume.config on each server or virtual machine

CAUTION:

To reconfigure volumes for the System services, you must complete this step before you run the setup script on each server or virtual machine.

You cannot change volumes for System services after running the script run or after starting the service hcpcs.service using systemd.

By default, each of the System services is configured not to use volumes for storage (each service uses the bind-mount option). To change this configuration, you can do that now in this step, before running the product startup scripts.

Tip: System services typically do not store a lot of data, so you should favor keeping the default bind-mount setting for them.

You configure volumes for HCP for cloud scale services later when using the deployment wizard.

To configure volumes for the System services:

On each server or virtual machine that is to be an HCP for cloud scale instance, use a text editor to open the file install_path/hcpcs/config/volume.config.
This file contains information about the volumes used by the System services. For each volume, the file contains lines that specify the following:
- The name of the volume:
  com.hds.ensemble.plugins.service.service_name.volume_name=volume_name
  
  Note: Do not edit the volume names. The default volume name values contain variables (SERVICE_PLUGIN_NAME and INSTANCE_UUID) that ensure that each volume gets a unique name.
- The volume driver that the volume uses:
  com.hds.ensemble.plugins.service.service_name.volume_driver=[volume_driver_name | bind-mount]
- The configuration options used by the volume driver. Each option is listed on its own line:
  com.hds.ensemble.plugins.service.service_name.volume_driver_opt_option_number=volume_driver_option_and_value
  For example, these lines describe the volume that the Admin-App service uses for storing its logs:
```
com.hds.ensemble.plugins.service.adminApp.log_volume_name=SERVICE_PLUGIN_NAME.INSTANCE_UUID.log
com.hds.ensemble.plugins.service.adminApp.log_volume_driver=bind-mount
com.hds.ensemble.plugins.service.adminApp.log_volume_driver_opt_1=hostpath=/home/hcpcs/log/com.hds.ensemble.plugins.service.adminApp/
```
For each volume that you want to configure, you can edit the following:
- The volume driver for the volume to use. To do this, replace bind-mount with the name of the volume driver you want.
  Volume drivers are provided by Docker and other third-party developers, not by the HCP for cloud scale system itself. For information on volume drivers, their capabilities, and their valid configuration settings, see the applicable Docker or third-party developer's documentation.
- On the line that contains _opt, the options for the volume driver.
  For information about the options you can configure, see the documentation for the volume driver that you're using.
  
  CAUTION:
  Option/value pairs can specify where data is written in each volume. These considerations apply:
  - Each volume that you can configure here must write data to a unique location.
  - The SERVICE_PLUGIN and INSTANCE_UUID variables cannot be used in option/value pairs.
  - Make sure the options and values you specify are valid. Incorrect options or values can cause system deployment to fail or volumes to be set up incorrectly. For information on configuration, see the volume driver's documentation.
  Tip: Create test volumes using the command docker volume create with your option/value pairs. Then, to test the volumes you've created, run the command docker run hello-world with the option --volume.

These lines show a service that has been configured to use the local-persist volume driver to store data:

com.hds.ensemble.plugins.service.marathon.data_volume_name=SERVICE_PLUGIN_NAME.INSTANCE_UUID.data
com.hds.ensemble.plugins.service.marathon.data_volume_driver=local-persist
com.hds.ensemble.plugins.service.marathon.data_volume_driver_opt_1=mountpoint=/home/hcpcs/data/com.hds.ensemble.plugins.service.marathon/