diff --git a/.github/workflows/pre-main.yaml b/.github/workflows/pre-main.yaml
index 7f672d5ae..a9642fb6b 100644
--- a/.github/workflows/pre-main.yaml
+++ b/.github/workflows/pre-main.yaml
@@ -232,6 +232,20 @@ jobs:
           max_attempts: 3
           command: cd ${GITHUB_WORKSPACE}/cnf-certification-test-partner && make bootstrap-cluster && make bootstrap-docker-ubuntu-local && make bootstrap-python-ubuntu-local && pip3 install pyyaml
 
+      # Restart docker using /mnt/docker-storage (sdb) instead of /var/lib/docker (sda).
+      # This step needs to be done right after the partner repo's bootstrap scripts, as they
+      # overwrite the docker's daemon.json.
+      - name: Make docker to use /mnt (sdb) for storage
+        run: |
+          df -h
+          lsblk
+          sudo mkdir /mnt/docker-storage
+          sudo jq '.  +={"data-root" : "/mnt/docker-storage"}' < /etc/docker/daemon.json > /tmp/docker-daemon.json
+          sudo cp /tmp/docker-daemon.json /etc/docker/daemon.json
+          cat /etc/docker/daemon.json
+          sudo systemctl restart docker
+          sudo ls -la /mnt/docker-storage
+
       - name: Run 'make rebuild-cluster'
         uses: nick-fields/retry@v3
         with:
@@ -327,6 +341,20 @@ jobs:
           max_attempts: 3
           command: cd ${GITHUB_WORKSPACE}/cnf-certification-test-partner && make bootstrap-cluster && make bootstrap-docker-ubuntu-local && make bootstrap-python-ubuntu-local && pip3 install pyyaml
 
+      # Restart docker using /mnt/docker-storage (sdb) instead of /var/lib/docker (sda).
+      # This step needs to be done right after the partner repo's bootstrap scripts, as they
+      # overwrite the docker's daemon.json.
+      - name: Make docker to use /mnt (sdb) for storage
+        run: |
+          df -h
+          lsblk
+          sudo mkdir /mnt/docker-storage
+          sudo jq '.  +={"data-root" : "/mnt/docker-storage"}' < /etc/docker/daemon.json > /tmp/docker-daemon.json
+          sudo cp /tmp/docker-daemon.json /etc/docker/daemon.json
+          cat /etc/docker/daemon.json
+          sudo systemctl restart docker
+          sudo ls -la /mnt/docker-storage
+
       - name: Run 'make rebuild-cluster'
         uses: nick-fields/retry@v3
         with: