[Linux] What are MDSS-related resources and how to perform disk cleanup?

This guide provides an overview of MDSS resources, including paths, containers, and volumes, along with actionable recommendations for managing disk space.

By following these guidelines, you can safely clean unnecessary files while maintaining the integrity of critical data.

Primary Cleanup Mechanism

The main method for managing disk space in MDSS is configuring the Database Retention Policy. This policy automatically removes outdated data based on retention settings, reducing manual cleanup requirements. For more information on setting up and using the retention policy, see the Database Retention Configuration Guide.

Filesystem Paths

MD Storage Security uses several paths on the host system for its operations. Below is a breakdown of their purposes and cleanup recommendations:

1. /etc/mdss the main installation directory containing Docker Compose files and the mdss.sh script.

2. /etc/mdss/services_logs stores MDSS container logs mounted from each running container.

   • Cleanup Guidance: Log cleanup is generally unnecessary if proper logging configurations are in place. To adjust logging levels or enable extra logging features, refer to How to Enable Extra Logging in the Configuration.

3. /var/log/mdss contains logs generated by MDSS scripts.

   • Cleanup Guidance: Can be safely cleaned if the logs are no longer needed.

4. /var/lib/docker houses all Docker container filesystems and volumes.

   • Important Note: Avoid making direct changes to this path. Use docker commands for all operations to prevent accidental data loss.

Docker Containers

MDSS services run inside Docker containers. Below are the key containers and their roles:

1. Containers with Names Starting with mdss_* and mdcs_* run MDSS services.
2. mdcs_rabbitmq provides RabbitMQ services for communication between MDSS components.
3. mdss_rediscache temporary data storage using Redis.
4. mdss_potgresql database container for persistent data, including settings, storage units, and processing history.

Docker Volumes

Volumes store persistent and temporary data required by MDSS. Here's an overview:

1. mdss_mongo_db stores the old MDSS database (persistent data).

   • Important Note: Do not delete this volume unless performing a clean reinstallation.

2. mdss_mongo_backup temporary old database files for backups.

   • Cleanup Guidance: Can be safely removed when MDSS is not running.

3. mdss_rediscache temporary data storage.

   • Cleanup Guidance: Can be safely removed when MDSS is not running.

4. mdss_postgres_data stores the MDSS database (persistent data).

   • Important Note: Do not delete this volume unless performing a clean reinstallation.

Useful Commands for Disk Usage Management

When investigating disk usage issues, use the following commands:

1. df -h displays overall disk usage in a human-readable format.
2. du -h <PATH> checks the size of a specific path on the system.
3. docker system df -v provides a detailed report of disk usage for Docker containers, images, and volumes.
4. docker system prune -a --volumes removes all unused containers, networks, images, and volumes.
   • Important Note: Make sure all MDSS services are running before executing this command to avoid removing critical data.

Additional Resources

• For more detailed information, refer to the Sizing Guide.
• We also recommend configuring an external database to enhance storage capacity for MDSS operations. For detailed instructions, please refer to the following article: Using an External Database.