diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index f71d1d39..c3d09f16 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -54,12 +54,10 @@ jobs:
       # TODO(fuweid): remove the env GO111MODULE=off in new version of go
       - name: install dependencies
         shell: bash
-        env:
-          GO111MODULE: off
         run: |
           echo "::group:: install dependencies"
-          go get -u -v github.com/vbatts/git-validation
-          go get -u -v github.com/kunalkushwaha/ltag
+          go install -v github.com/vbatts/git-validation@@latest
+          go install -v github.com/kunalkushwaha/ltag@@latest
           echo "::endgroup::"
 
       - name: DCO checker
diff --git a/.github/workflows/ci-userspace-convertor.yml b/.github/workflows/ci-userspace-convertor.yml
index cb996a81..eb1a780f 100644
--- a/.github/workflows/ci-userspace-convertor.yml
+++ b/.github/workflows/ci-userspace-convertor.yml
@@ -70,6 +70,9 @@ jobs:
           /opt/overlaybd/snapshotter/convertor -r localhost:5000/redis -i 7.2.3 --overlaybd 7.2.3_overlaybd --turboOCI 7.2.3_turbo
           bash run_container.sh localhost:5000/redis:7.2.3_overlaybd
           bash run_container.sh localhost:5000/redis:7.2.3_turbo
+          /opt/overlaybd/snapshotter/convertor -r localhost:5000/redis -i 7.2.3 --overlaybd 7.2.3_overlaybd_256 --turboOCI 7.2.3_turbo_256 --vsize 256
+          bash run_container.sh localhost:5000/redis:7.2.3_overlaybd_256
+          bash run_container.sh localhost:5000/redis:7.2.3_turbo_256
 
       - name: CI - uconv E2E with digest input
         working-directory: ci/scripts
diff --git a/ci/scripts/run_container.sh b/ci/scripts/run_container.sh
index f34c45a2..928c1127 100755
--- a/ci/scripts/run_container.sh
+++ b/ci/scripts/run_container.sh
@@ -2,6 +2,8 @@
 #
 # rpull and run on-demand
 
+set -x
+
 image=$1
 container_name=${2:-test}
 
@@ -11,6 +13,7 @@ exit_code=0
 if ! ctr run -d --net-host --snapshotter=overlaybd "${image}" "${container_name}"; then
   exit_code=1
 fi
+lsblk
 if ! ctr t ls | grep "${container_name}"; then
   exit_code=1
 fi
diff --git a/cmd/convertor/builder/turboOCI_builder.go b/cmd/convertor/builder/turboOCI_builder.go
index f7742048..f11bd3ff 100644
--- a/cmd/convertor/builder/turboOCI_builder.go
+++ b/cmd/convertor/builder/turboOCI_builder.go
@@ -262,8 +262,8 @@ func (e *turboOCIBuilderEngine) createIdentifier(idx int) error {
 }
 
 func (e *turboOCIBuilderEngine) create(ctx context.Context, dir string, mkfs bool) error {
-	vsizeGB := 64
-	if mkfs {
+	vsizeGB := 64 // use default baselayer
+	if e.mkfs {
 		vsizeGB = e.vsize
 	}
 	opts := []string{"-s", fmt.Sprintf("%d", vsizeGB), "--turboOCI"}