Agent Migration Log: Moving SQL Server from VPS to Localhost
This document outlines a session using an AI agent to migrate a SQL Server Docker container and its data volume from a remote host backup (SSDNodes) to a local Linux machine. It highlights the agent’s ability to plan, adapt to user constraints, and self-correct configuration errors.
The Objective
User Prompt:
“In this dir are two files, a docker compose file and a docker volume backup. These come from my hosted ssdnodes.com vps. Your task is to migrate these to this machine. ~/docker-containers/sqlserver is where they should live on this computer. Let me know if you understand the task. Make a plan and get my approval before acting”
Phase 1: Context & Planning
The agent first analyzed the source directory, identifying docker-compose.yml and a 692MB volume backup sqlserver-data.tar.gz. It initially proposed a standard migration, but the user intervened to refine the storage strategy.
User Instruction:
“So we need a volume on this computer, and the docker-compose.yml needs to be changed to refer to it. Don’t worry about the password being in the compose file”
The agent adjusted the plan to use a local bind mount. However, the user corrected this to prefer a Docker Named Volume.
User Instruction:
“I liked named volume, but it still needs to point to where we unarchive the data”
Final Plan Formulation: The agent synthesized a complex plan to satisfy the “Named Volume” requirement while ensuring the archived data was correctly injected into it:
- Keep the named volume architecture.
- Manually create the volume
sqlserver-data. - Complex Step: Use a temporary utility container to mount both the new volume and the backup data to perform the extraction (injecting the data into the managed volume).
Phase 2: Execution Highlights
1. Volume Creation & Data Injection
Instead of just unzipping the file, the agent had to “sideload” the data into the Docker volume system.
- Step A: Extracted the tarball to a temporary location (
/tmp/sqlserver-restore). - Step B: Used a temporary Ubuntu container to copy the data into the Docker volume.
# Agent logic: Mount the named volume to /var/opt/mssql and the temp files to /backup
docker run --rm -v sqlserver-data:/var/opt/mssql -v /tmp/sqlserver-restore:/backup ubuntu bash -c "cp -a /backup/. /var/opt/mssql/"
2. The “Agent Save” (Self-Correction)
After injecting the data, the agent attempted to start the container using docker compose up.
The Issue:
The agent noticed that Docker Compose automatically created a new namespaced volume (sqlserver_sqlserver-data) rather than using the sqlserver-data volume the agent had just meticulously populated.
The Fix:
Without requiring user intervention, the agent recognized the configuration drift, stopped the container, removed the empty volume, and rewrote the docker-compose.yml to explicitly tag the volume as external.
Agent applied edit to docker-compose.yml:
volumes:
sqlserver-data:
external: true # Added by agent to force usage of the populated volume
3. Verification & Handover
The agent successfully started the container. It scanned the logs to confirm that the databases from the backup (dbBasics, dbTester, JProCo, etc.) were initializing.
User Issue:
“The TCP/IP connection to the host localhost, port 1433 has failed.”
Agent Resolution:
The agent checked the port mappings and reminded the user that the docker-compose.yml mapped the internal SQL port (1433) to a custom host port.
“The container is running and mapped to port 5433 on localhost… Try connecting to localhost:5433.”
Summary: The agent successfully migrated a database container by orchestrating file operations, complex volume mounting commands, and editing configuration files to resolve naming conflicts, effectively cloning the VPS environment to the local home lab.