V‑Blaze system internals

The following sections detail the fundamental components of an existing V‑Blaze deployment; including, core services, directory structure, networking, security, backup information, and various logs.

Core services

V‑Blaze software is comprised of two core components:


The primary ASR engine service responsible for transcription.


The front-end API service. vociwebapi enables remote clients to communicate with vociserver via a REST API.

Note: The vociserver and vociwebapi services must be running for transcription to work. Refer to V‑Blaze service commands for more information on checking the status of services.

Directory structure

V‑Blaze software components, state information, and logging can be found in the following directories:


Root directory for the V‑Blaze software installation


Installation directory for the vociserver service software


Installation directory for the vociwebapi service software


Installation directory for language models


Stateful information used for licensing and field tuning (substitution and redaction rules)


Log directory for the vociserver service


Log directory for the vociwebapi service

Identifying installed products

Use the following commands to identify the components of the V‑Blaze software installed on the system:

Identify all Voci products

rpm -qa voci-\* | sort
Identify the vociserver service components

rpm -qa voci-server-\* | sort
Identify the vociwebapi service components

rpm -qa voci-webapi\*
Identify installed language and associated acoustic models

rpm -qa voci-langpack\* | sort


V‑Blaze communicates in a client-server RESTful API method using port 17171 on the server through the vociwebapi service. The vociwebapi service communicates to the vociserver service (ASR engine) using port 17170 on localhost, where both the vociserver and vociwebapi services are installed and running.

In most cases, 17170 does not need to be accessed externally except in some specialized configurations such as real-time transcription.

Note: The vociserver processes require outbound network access to the Voci license server (typically https://license.vocitec.com/ using TCP port 443). Proxy servers can be configured for licensing connections in environments where direct connection is not permitted.

Any client trying to communicate with V‑Blaze must have network access across all network segments between the two end points over port 17171.


V‑Blaze's ASR engine processes all audio transcription requests in memory and does not store any request data on system storage. The system requires a mount point (/opt/voci/ramfs/), but any data there is temporary. All vociserver and vociwebapi processes run under the vocisrv restricted user. This user is a mandatory service account that does not require a home directory or login credentials.

Note: If antivirus software is running on a V‑Blaze server, Voci recommends excluding all Voci processes (and language models) from automatic scanning to avoid excessive delays during startup or processing.


As V‑Blaze does not store any audio data or transcripts locally once the processing has been completed, there is likely no critical data on the host worth backing up. All audio and transcript data is stored in RAM during processing.

Tip: It is good practice to back up configuration files to maintain settings across multiple systems or be able to restore a V‑Blaze installation if required.


There are two locations where log files associated with V‑Blaze are located, relating to each of the core services:


Logs are located in the /var/log/vociserver/ directory.


Logs are located in the /var/log/vociwebapi/ directory.

The following table explains the various types of logs stored in each location:

Table 1. V‑Blaze Event Logs

Log file



Look for serving on port 17170 to verify that the vociserver service started properly and is ready to accept requests.

Errors are logged in this file to assist with troubleshooting.


Logs updates to and from Voci's Internet License Server.


Detailed logging of each submitted API request.

Enabled by defining accesslog=true in the webapi.cfg configuration file located in /opt/voci/state/ directory.

Note that access.log will not be written unless defined in the webapi.cfg config file.


Look for listening on port 17171 to verify that the vociwebapi process started properly and is ready to accept requests.

Errors are logged in this file to assist with troubleshooting.