Differences

This shows you the differences between two versions of the page.

--- migrating_mariadb_between_hosts [2025/04/13 01:56] – created oso
+++ migrating_mariadb_between_hosts [2025/04/13 02:01] (current) – [📦 Notes on Volume Migration and Backup] oso
@@ Line 88: / Line 88: @@
 . Find the volume's path on the source server:
-    <code bash>
+<code bash>
-    docker inspect mariadb | grep Source
+docker inspect mariadb | grep Source
-    </code>
+</code>
 . Stop the container, then tar the volume contents:
-    <code bash>
+<code bash>
-    docker stop mariadb
+docker stop mariadb
-    sudo tar -czvf mariadb_data.tar.gz /var/lib/docker/volumes/your_volume_name/_data
+sudo tar -czvf mariadb_data.tar.gz /var/lib/docker/volumes/your_volume_name/_data
-    </code>
+</code>
 . Copy the `.tar.gz` to the new server:
-    <code bash>
+<code bash>
-    scp mariadb_data.tar.gz user@newserver:~
+scp mariadb_data.tar.gz user@newserver:~
-    </code>
+</code>
 . Extract into a Docker volume path (on the new server):
-    <code bash>
+<code bash>
-    docker volume create mariadb_data
+docker volume create mariadb_data
-    sudo tar -xzvf mariadb_data.tar.gz -C /var/lib/docker/volumes/mariadb_data/_data
+sudo tar -xzvf mariadb_data.tar.gz -C /var/lib/docker/volumes/mariadb_data/_data
-    </code>
+</code>
 . Now `docker compose up -d` with the same `docker-compose.yml`, and your DB will be live.
@@ Line 116: / Line 116: @@
 ---
+Example for copying the volume:
+<code bash>
+#!/bin/bash
+set -e
+VOLUME_ID="4042cf30bc39026f2b18ef4f2fcd2893470efba3637f5e18f1a762856debba0d"
+VOLUME_PATH="/var/lib/docker/volumes/${VOLUME_ID}/_data"
+ARCHIVE_NAME="mariadb_volume_backup.tar.gz"
+DEST_HOST="[email protected]"
+DEST_PATH="/tmp"
+echo "==> Stopping any container using the volume..."
+docker ps -q --filter volume="$VOLUME_ID" | while read cid; do
+    docker stop "$cid"
+done
+echo "==> Creating archive from volume data..."
+sudo tar -czf "$ARCHIVE_NAME" -C "$VOLUME_PATH" .
+echo "==> Copying archive to destination server..."
+scp "$ARCHIVE_NAME" "$DEST_HOST:$DEST_PATH"
+echo "==> Done. You can now restore it on serv1 using the corresponding import steps."
+</code>
+then restore in the destination server...
+<code bash>
+#!/bin/bash
+set -e
+VOLUME_ID="mariadb_restored_volume"
+ARCHIVE_PATH="/tmp/mariadb_volume_backup.tar.gz"
+VOLUME_PATH="/var/lib/docker/volumes/${VOLUME_ID}/_data"
+echo "==> Creating target volume..."
+docker volume create "$VOLUME_ID"
+echo "==> Extracting data into new volume..."
+sudo tar -xzf "$ARCHIVE_PATH" -C "$VOLUME_PATH"
+echo "==> Fixing permissions..."
+sudo chown -R 999:999 "$VOLUME_PATH"  # 999 is default mysql UID/GID in official image
+echo "==> Starting MariaDB container..."
+docker run -d \
+  --name mariadb \
+  -v "${VOLUME_ID}:/var/lib/mysql" \
+  -e MYSQL_ROOT_PASSWORD=your_root_pass \
+  -p 3306:3306 \
+  mariadb:latest
+echo "==> Done! MariaDB should be up with old data."
+</code>
 ===== ✅ Final Thoughts =====