Prune old call recordings

How to automatically delete call recordings older than a specified number of days on NethVoice

Guide Objective

The purpose of this guide is to explain how to configure automatic call recording pruning on NethVoice and to describe the setup, operation, and data cleanup procedures to ensure safe deletion of old recordings.

Introduction

NethVoice stores call recordings as files in the file system and maintains metadata references in a MariaDB database. Over time, recordings can consume significant disk space. The recording pruning feature allows you to automatically delete both recording files and their database metadata for recordings older than a configurable number of days (default: 10 days) using systemd timers and services.

How it Works

• A systemd timer triggers a service every day at midnight.
• The service first removes database metadata references for old recordings.
• The service then deletes the actual recording files from the file system.
• The retention period is configurable (default: 10 days).
• Deleted recordings and their metadata are permanently removed.

Use Cases

• Disk space management: Prevent file system bloat by removing old recordings automatically.
• Data retention compliance: Maintain organization-specific retention policies for call records.
• Performance optimization: Keeping the database lean improves query performance.

Prerequisites

• SSH access to the NethServer 8 cluster where NethVoice is running.
• Familiarity with systemd user services.

Setup Instructions

Step 1: Access the Application

First, connect to NethServer using SSH, then access the NethVoice container environment:

runagent -m nethvoice1

Then navigate to the systemd user directory:

cd ~/.config/systemd/user/

(The full path is /home/nethvoice1/.config/systemd/user/)

Step 2: Create the Timer File

Create a file named recording-prune.timer with the following content:

File: recording-prune.timer

[Unit]
Description=Daily timer to prune old call recordings

[Timer]
OnCalendar=daily
Persistent=true

[Install]
WantedBy=timers.target

This file defines a daily timer that triggers the pruning service every day. The Persistent=true setting ensures the timer runs even if the system was shut down at the scheduled time.

Step 3: Create the Service File

Create a file named recording-prune.service with the following content:

File: recording-prune.service

[Unit]
Description=Prune old call recordings
Wants=recording-prune.timer

[Service]
Type=oneshot
Environment=PODMAN_SYSTEMD_UNIT=%n
EnvironmentFile=%S/state/passwords.env
WorkingDirectory=%S/state
Environment=DAYS=10
ExecStart=/bin/bash -c "podman exec -i mariadb mysql -uroot -p\"${MARIADB_ROOT_PASSWORD}\" asteriskcdrdb -e \"UPDATE asteriskcdrdb.cdr SET recordingfile = '' WHERE calldate < DATE_SUB(NOW(), INTERVAL ${DAYS} DAY) AND recordingfile != '';\""
ExecStart=podman exec -ti freepbx find /var/spool/asterisk/monitor/ -type f -mtime +${DAYS} -delete

The Environment=DAYS=10 line sets the retention period to 10 days. You can change this value to modify how many days of recordings to retain.

Note: The service uses two separate ExecStart commands:

• The first command updates the database to clear recording file references.
• The second command deletes the actual recording files from disk.

Step 4: Enable and Start the Timer

Enable the timer to start automatically at boot:

systemctl --user daemon-reload
systemctl --user enable --now recording-prune.timer

Done! The recording pruning service is now configured to run once a day.

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Backup and Restore Procedures

Before relying on automatic pruning in production, it is strongly recommended to create backups of your recording data.

Before executing any commands, ensure you are in the NethVoice application environment:

runagent -m nethvoice1

Backing Up Recording Metadata

To back up the call recording metadata from the CDR table:

export MARIADB_ROOT_PASSWORD="$(awk -F= '/^MARIADB_ROOT_PASSWORD=/{sub(/^[^=]*=/,""); print}' ~/.config/state/passwords.env)"
podman exec -ti mariadb mysqldump -p$MARIADB_ROOT_PASSWORD -uroot asteriskcdrdb cdr > cdr_backup.dump

This command:

• Extracts the MariaDB root password from the passwords.env file.
• Uses mysqldump to export the CDR table to a file named cdr_backup.dump inside the host environment.

Backing Up Recording Files

To back up the actual recording files:

podman exec freepbx tar -cz /var/spool/asterisk/monitor/ > recordings_backup.tar.gz

Restoring Metadata from a Backup

To restore the CDR table from a backup:

podman cp cdr_backup.dump mariadb:/tmp
podman exec -ti mariadb /bin/bash -c "mysql -p$MARIADB_ROOT_PASSWORD -uroot asteriskcdrdb < /tmp/cdr_backup.dump"

This command:

• Copies the backup file into the MariaDB container.
• Restores the CDR data from the backup using the mysql command.

Restoring Recording Files from a Backup

To restore the actual recording files:

podman cp recordings_backup.tar.gz freepbx:/tmp
podman exec -ti freepbx /bin/bash -c "tar -xz -C / -f /tmp/recordings_backup.tar.gz"
podman exec -ti freepbx chown -R asterisk:asterisk /var/spool/asterisk/monitor/
podman exec -ti freepbx rm /tmp/recordings_backup.tar.gz

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Management and Troubleshooting

Run Service Manually

To test the pruning service manually:

systemctl --user start recording-prune.service

Check Timer Status

To view the timer and its last execution:

systemctl --user status recording-prune.timer

View Service Logs

To see the output of the pruning service:

api-server-logs logs --entity module --name nethvoice1

This displays the logs for the NethVoice module. Look for entries related to the recording pruning service:

2026-01-20T13:51:42Z [1:nethvoice1:systemd] Starting Prune old call recordings...
2026-01-20T13:51:42Z [1:nethvoice1:systemd] Finished Prune old call recordings.

Adjust the Retention Period

To change the retention period from the default 10 days:

1. Edit the recording-prune.service file.
2. Locate the line: Environment=DAYS=10
3. Replace 10 with your desired number of days.
4. Save the file.
5. Reload the systemd user daemon: systemctl --user daemon-reload

Verify Recording Deletion

To verify that recordings were deleted, check the recording directory:

ls -lah /var/spool/asterisk/monitor/

You can also query the CDR table to see which recordings have empty file references:

podman exec -ti mariadb mysql -uroot -p$MARIADB_ROOT_PASSWORD -e "SELECT COUNT(*) FROM asteriskcdrdb.cdr WHERE recordingfile = '' AND calldate < DATE_SUB(NOW(), INTERVAL 10 DAY);"

Disable the Pruning Service

To disable the timer and stop automatic pruning:

systemctl --user disable --now recording-prune.timer

To remove the service and timer files:

rm ~/.config/systemd/user/recording-prune.service
rm ~/.config/systemd/user/recording-prune.timer
systemctl --user daemon-reload

Common Issues

Timer not running:

• Check if the timer is enabled: systemctl --user list-timers
• Verify the service files are in the correct location: ls -la ~/.config/systemd/user/recording-prune.*
• Reload the systemd user daemon: systemctl --user daemon-reload

Database connection errors:

• Confirm the MariaDB container is running: podman ps | grep mariadb
• Test the MariaDB connection manually using the provided credentials.

Files not being deleted:

• Verify the FreePBX container is running: podman ps | grep freepbx
• Check the permissions on the /var/spool/asterisk/monitor/ directory.
• Ensure the DAYS environment variable matches the intended retention period.