diff --git a/lib/filestream/filestream.go b/lib/filestream/filestream.go
index 6b5b3d233..4be2fa82e 100644
--- a/lib/filestream/filestream.go
+++ b/lib/filestream/filestream.go
@@ -64,10 +64,7 @@ func (r *Reader) Path() string {
 //
 // If nocache is set, then the reader doesn't pollute OS page cache.
 func OpenReaderAt(path string, offset int64, nocache bool) (*Reader, error) {
-	r, err := Open(path, nocache)
-	if err != nil {
-		return nil, err
-	}
+	r := MustOpen(path, nocache)
 	n, err := r.f.Seek(offset, io.SeekStart)
 	if err != nil {
 		r.MustClose()
@@ -80,13 +77,13 @@ func OpenReaderAt(path string, offset int64, nocache bool) (*Reader, error) {
 	return r, nil
 }
 
-// Open opens the file from the given path in nocache mode.
+// MustOpen opens the file from the given path in nocache mode.
 //
 // If nocache is set, then the reader doesn't pollute OS page cache.
-func Open(path string, nocache bool) (*Reader, error) {
+func MustOpen(path string, nocache bool) *Reader {
 	f, err := os.Open(path)
 	if err != nil {
-		return nil, err
+		logger.Panicf("FATAL: cannot open file: %s", err)
 	}
 	r := &Reader{
 		f:  f,
@@ -96,10 +93,10 @@ func Open(path string, nocache bool) (*Reader, error) {
 		r.st.fd = f.Fd()
 	}
 	readersCount.Inc()
-	return r, nil
+	return r
 }
 
-// MustClose closes the underlying file passed to Open.
+// MustClose closes the underlying file passed to MustOpen.
 func (r *Reader) MustClose() {
 	if err := r.st.close(); err != nil {
 		logger.Panicf("FATAL: cannot close streamTracker for file %q: %s", r.f.Name(), err)
diff --git a/lib/filestream/filestream_test.go b/lib/filestream/filestream_test.go
index a0d56973b..cf3223ac1 100644
--- a/lib/filestream/filestream_test.go
+++ b/lib/filestream/filestream_test.go
@@ -42,10 +42,7 @@ func testWriteRead(t *testing.T, nocache bool, testStr string) {
 	}
 	w.MustClose()
 
-	r, err := Open("./nocache_test.txt", nocache)
-	if err != nil {
-		t.Fatalf("cannot open file: %s", err)
-	}
+	r := MustOpen("./nocache_test.txt", nocache)
 	buf := make([]byte, len(testStr))
 	if _, err := io.ReadFull(r, buf); err != nil {
 		t.Fatalf("unexpected error when reading: %s", err)
diff --git a/lib/mergeset/block_stream_reader.go b/lib/mergeset/block_stream_reader.go
index c2d4a3d3d..8a4f729fe 100644
--- a/lib/mergeset/block_stream_reader.go
+++ b/lib/mergeset/block_stream_reader.go
@@ -148,36 +148,23 @@ func (bsr *blockStreamReader) InitFromFilePart(path string) error {
 	}
 
 	metaindexPath := filepath.Join(path, metaindexFilename)
-	metaindexFile, err := filestream.Open(metaindexPath, true)
-	if err != nil {
-		return fmt.Errorf("cannot open metaindex file in stream mode: %w", err)
-	}
+	metaindexFile := filestream.MustOpen(metaindexPath, true)
+
+	var err error
 	bsr.mrs, err = unmarshalMetaindexRows(bsr.mrs[:0], metaindexFile)
 	metaindexFile.MustClose()
 	if err != nil {
-		return fmt.Errorf("cannot unmarshal metaindex rows from file %q: %w", metaindexPath, err)
+		logger.Panicf("FATAL: cannot unmarshal metaindex rows from file %q: %s", metaindexPath, err)
 	}
 
 	indexPath := filepath.Join(path, indexFilename)
-	indexFile, err := filestream.Open(indexPath, true)
-	if err != nil {
-		return fmt.Errorf("cannot open index file in stream mode: %w", err)
-	}
+	indexFile := filestream.MustOpen(indexPath, true)
 
 	itemsPath := filepath.Join(path, itemsFilename)
-	itemsFile, err := filestream.Open(itemsPath, true)
-	if err != nil {
-		indexFile.MustClose()
-		return fmt.Errorf("cannot open items file in stream mode: %w", err)
-	}
+	itemsFile := filestream.MustOpen(itemsPath, true)
 
 	lensPath := filepath.Join(path, lensFilename)
-	lensFile, err := filestream.Open(lensPath, true)
-	if err != nil {
-		indexFile.MustClose()
-		itemsFile.MustClose()
-		return fmt.Errorf("cannot open lens file in stream mode: %w", err)
-	}
+	lensFile := filestream.MustOpen(lensPath, true)
 
 	bsr.path = path
 	bsr.indexReader = indexFile
diff --git a/lib/mergeset/part.go b/lib/mergeset/part.go
index 194f11b60..7ee86dffc 100644
--- a/lib/mergeset/part.go
+++ b/lib/mergeset/part.go
@@ -74,10 +74,7 @@ func openFilePart(path string) (*part, error) {
 	}
 
 	metaindexPath := filepath.Join(path, metaindexFilename)
-	metaindexFile, err := filestream.Open(metaindexPath, true)
-	if err != nil {
-		return nil, fmt.Errorf("cannot open %q: %w", metaindexPath, err)
-	}
+	metaindexFile := filestream.MustOpen(metaindexPath, true)
 	metaindexSize := fs.MustFileSize(metaindexPath)
 
 	indexPath := filepath.Join(path, indexFilename)
diff --git a/lib/persistentqueue/persistentqueue.go b/lib/persistentqueue/persistentqueue.go
index 6ce06fd29..7a548f94e 100644
--- a/lib/persistentqueue/persistentqueue.go
+++ b/lib/persistentqueue/persistentqueue.go
@@ -100,10 +100,7 @@ func (q *queue) mustResetFiles() {
 	q.writer = w
 
 	q.readerPath = q.writerPath
-	r, err := filestream.Open(q.readerPath, true)
-	if err != nil {
-		logger.Panicf("FATAL: cannot open chunk file %q: %s", q.readerPath, err)
-	}
+	r := filestream.MustOpen(q.readerPath, true)
 	q.reader = r
 
 	if err := q.flushMetainfo(); err != nil {
@@ -559,10 +556,7 @@ func (q *queue) nextChunkFileForRead() error {
 	}
 	q.readerLocalOffset = 0
 	q.readerPath = q.chunkFilePath(q.readerOffset)
-	r, err := filestream.Open(q.readerPath, true)
-	if err != nil {
-		return fmt.Errorf("cannot open chunk file %q: %w", q.readerPath, err)
-	}
+	r := filestream.MustOpen(q.readerPath, true)
 	q.reader = r
 	if err := q.flushMetainfo(); err != nil {
 		return fmt.Errorf("cannot flush metainfo: %w", err)
diff --git a/lib/storage/block_stream_reader.go b/lib/storage/block_stream_reader.go
index 58e24c6c1..8087c2388 100644
--- a/lib/storage/block_stream_reader.go
+++ b/lib/storage/block_stream_reader.go
@@ -135,41 +135,20 @@ func (bsr *blockStreamReader) InitFromFilePart(path string) error {
 	}
 
 	timestampsPath := filepath.Join(path, timestampsFilename)
-	timestampsFile, err := filestream.Open(timestampsPath, true)
-	if err != nil {
-		return fmt.Errorf("cannot open timestamps file in stream mode: %w", err)
-	}
+	timestampsFile := filestream.MustOpen(timestampsPath, true)
 
 	valuesPath := filepath.Join(path, valuesFilename)
-	valuesFile, err := filestream.Open(valuesPath, true)
-	if err != nil {
-		timestampsFile.MustClose()
-		return fmt.Errorf("cannot open values file in stream mode: %w", err)
-	}
+	valuesFile := filestream.MustOpen(valuesPath, true)
 
 	indexPath := filepath.Join(path, indexFilename)
-	indexFile, err := filestream.Open(indexPath, true)
-	if err != nil {
-		timestampsFile.MustClose()
-		valuesFile.MustClose()
-		return fmt.Errorf("cannot open index file in stream mode: %w", err)
-	}
+	indexFile := filestream.MustOpen(indexPath, true)
 
 	metaindexPath := filepath.Join(path, metaindexFilename)
-	metaindexFile, err := filestream.Open(metaindexPath, true)
-	if err != nil {
-		timestampsFile.MustClose()
-		valuesFile.MustClose()
-		indexFile.MustClose()
-		return fmt.Errorf("cannot open metaindex file in stream mode: %w", err)
-	}
+	metaindexFile := filestream.MustOpen(metaindexPath, true)
 	mrs, err := unmarshalMetaindexRows(bsr.mrs[:0], metaindexFile)
 	metaindexFile.MustClose()
 	if err != nil {
-		timestampsFile.MustClose()
-		valuesFile.MustClose()
-		indexFile.MustClose()
-		return fmt.Errorf("cannot unmarshal metaindex rows from file part %q: %w", metaindexPath, err)
+		logger.Panicf("FATAL: cannot unmarshal metaindex rows from file part %q: %s", metaindexPath, err)
 	}
 
 	bsr.path = path
diff --git a/lib/storage/part.go b/lib/storage/part.go
index de917b427..3882bc79f 100644
--- a/lib/storage/part.go
+++ b/lib/storage/part.go
@@ -67,13 +67,7 @@ func openFilePart(path string) (*part, error) {
 	indexSize := fs.MustFileSize(indexPath)
 
 	metaindexPath := filepath.Join(path, metaindexFilename)
-	metaindexFile, err := filestream.Open(metaindexPath, true)
-	if err != nil {
-		timestampsFile.MustClose()
-		valuesFile.MustClose()
-		indexFile.MustClose()
-		return nil, fmt.Errorf("cannot open metaindex file: %w", err)
-	}
+	metaindexFile := filestream.MustOpen(metaindexPath, true)
 	metaindexSize := fs.MustFileSize(metaindexPath)
 
 	size := timestampsSize + valuesSize + indexSize + metaindexSize