diff --git a/.gitignore b/.gitignore
index 0e18666..2f7c206 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,4 @@ var/job.db-shm
 var/job.db-wal
 
 dist/
+*.db
diff --git a/internal/util/fstat.go b/internal/util/fstat.go
index 3361e39..0c84014 100644
--- a/internal/util/fstat.go
+++ b/internal/util/fstat.go
@@ -1,4 +1,4 @@
-// Copyright (C) 2022 NHR@FAU, University Erlangen-Nuremberg.
+// Copyright (C) 2023 NHR@FAU, University Erlangen-Nuremberg.
 // All rights reserved.
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
@@ -20,6 +20,7 @@ func GetFilesize(filePath string) int64 {
 	fileInfo, err := os.Stat(filePath)
 	if err != nil {
 		log.Errorf("Error on Stat %s: %v", filePath, err)
+		return 0
 	}
 	return fileInfo.Size()
 }
@@ -28,6 +29,7 @@ func GetFilecount(path string) int {
 	files, err := os.ReadDir(path)
 	if err != nil {
 		log.Errorf("Error on ReadDir %s: %v", path, err)
+		return 0
 	}
 
 	return len(files)
diff --git a/internal/util/util_test.go b/internal/util/util_test.go
new file mode 100644
index 0000000..a318649
--- /dev/null
+++ b/internal/util/util_test.go
@@ -0,0 +1,71 @@
+// Copyright (C) 2023 NHR@FAU, University Erlangen-Nuremberg.
+// All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+package util_test
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/ClusterCockpit/cc-backend/internal/util"
+)
+
+func TestCheckFileExists(t *testing.T) {
+	tmpdir := t.TempDir()
+	filePath := filepath.Join(tmpdir, "version.txt")
+
+	if err := os.WriteFile(filePath, []byte(fmt.Sprintf("%d", 1)), 0666); err != nil {
+		t.Fatal(err)
+	}
+	if !util.CheckFileExists(filePath) {
+		t.Fatal("expected true, got false")
+	}
+
+	filePath = filepath.Join(tmpdir, "version-test.txt")
+	if util.CheckFileExists(filePath) {
+		t.Fatal("expected false, got true")
+	}
+}
+
+func TestGetFileSize(t *testing.T) {
+	tmpdir := t.TempDir()
+	filePath := filepath.Join(tmpdir, "data.json")
+
+	if s := util.GetFilesize(filePath); s > 0 {
+		t.Fatalf("expected 0, got %d", s)
+	}
+
+	if err := os.WriteFile(filePath, []byte(fmt.Sprintf("%d", 1)), 0666); err != nil {
+		t.Fatal(err)
+	}
+	if s := util.GetFilesize(filePath); s == 0 {
+		t.Fatal("expected not 0, got 0")
+	}
+}
+
+func TestGetFileCount(t *testing.T) {
+	tmpdir := t.TempDir()
+
+	if c := util.GetFilecount(tmpdir); c != 0 {
+		t.Fatalf("expected 0, got %d", c)
+	}
+
+	filePath := filepath.Join(tmpdir, "data-1.json")
+	if err := os.WriteFile(filePath, []byte(fmt.Sprintf("%d", 1)), 0666); err != nil {
+		t.Fatal(err)
+	}
+	filePath = filepath.Join(tmpdir, "data-2.json")
+	if err := os.WriteFile(filePath, []byte(fmt.Sprintf("%d", 1)), 0666); err != nil {
+		t.Fatal(err)
+	}
+	if c := util.GetFilecount(tmpdir); c != 2 {
+		t.Fatalf("expected 2, got %d", c)
+	}
+
+	if c := util.GetFilecount(filePath); c != 0 {
+		t.Fatalf("expected 0, got %d", c)
+	}
+}
diff --git a/pkg/archive/archive_test.go b/pkg/archive/archive_test.go
index b41a033..5523a21 100644
--- a/pkg/archive/archive_test.go
+++ b/pkg/archive/archive_test.go
@@ -1,4 +1,4 @@
-// Copyright (C) 2022 NHR@FAU, University Erlangen-Nuremberg.
+// Copyright (C) 2023 NHR@FAU, University Erlangen-Nuremberg.
 // All rights reserved.
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
diff --git a/pkg/archive/fsBackend.go b/pkg/archive/fsBackend.go
index b58891f..cb8ed69 100644
--- a/pkg/archive/fsBackend.go
+++ b/pkg/archive/fsBackend.go
@@ -348,7 +348,7 @@ func (fsa *FsArchive) Compress(jobs []*schema.Job) {
 
 	for _, job := range jobs {
 		fileIn := getPath(job, fsa.path, "data.json")
-		if !util.CheckFileExists(fileIn) && util.GetFilesize(fileIn) > 2000 {
+		if util.CheckFileExists(fileIn) && util.GetFilesize(fileIn) > 2000 {
 			util.CompressFile(fileIn, getPath(job, fsa.path, "data.json.gz"))
 			cnt++
 		}