Volumes

Volumes provide persistent storage for your game servers. Without volumes, all data inside a container is lost when the server is stopped.

How Volumes Work

Each volume mount maps a path inside the container to a directory on the host machine. When the game server writes files to the mounted path, those files are actually stored on the host — outside the container.

Host: /opt/cosy/volumes/<volume-mount-uuid>
        ↕ (mounted)
Container: /data

The host-side path is managed entirely by COSY — each volume mount gets an internal UUID that isn't visible in the UI. You don't need to know or interact with this path directly. Instead, use the File Browser to access your server files.

Configuring Volume Mounts

In the Settings view, you can add volume mounts by specifying:

COSY automatically manages the host-side path. Each volume mount is stored under the COSY volumes directory (default: /opt/cosy/volumes) with an auto-generated UUID as the directory name.

Host Mounts (Advanced)

In addition to COSY-managed volumes, a server can bind-mount an explicit host path into the container. Host mounts are configured under Advanced Settings (in the creation wizard and the server settings) by specifying:

Unlike regular volumes, the host-side path is not managed by COSY — you point directly at a directory or file on the host. Because this grants access to arbitrary host paths, only administrators (Admin or Owner) can create or change host mounts. Templates may also define host mounts via the host_mounts field; these default to read-only and are subject to the same restriction at creation time.

Data Lifecycle

• Server start — Volumes are mounted into the new container
• Server stop — Container is removed, volumes remain on disk
• Server restart — New container mounts the same volumes, data is preserved
• Server delete — Volumes are cleaned up along with the server

Accessing Volume Files

You can browse and edit files in your volumes through the File Browser in the COSY web interface.