Don't delete redundant postdata files

initialization/initialization.go

@@ -295,9 +295,6 @@ func (init *Initializer) Initialize(ctx context.Context) error {
 		zap.Int("firstFileIndex", layout.FirstFileIdx),
 		zap.Int("lastFileIndex", layout.LastFileIdx),
 	)
-	if err := removeRedundantFiles(init.cfg, init.opts, init.logger); err != nil {
-		return err
-	}
 
 	numLabels := uint64(init.opts.NumUnits) * init.cfg.LabelsPerUnit
 	difficulty := init.powDifficultyFunc(numLabels)
@@ -395,36 +392,6 @@ func (init *Initializer) Initialize(ctx context.Context) error {
 	return fmt.Errorf("no nonce found")
 }
 
-func removeRedundantFiles(cfg config.Config, opts config.InitOpts, logger *zap.Logger) error {
-	// Go over all postdata_N.bin files in the data directory and remove the ones that are not needed.
-	// The files with indices from 0 to init.opts.TotalFiles(init.cfg.LabelsPerUnit) - 1 are preserved.
-	// The rest are redundant and can be removed.
-	maxFileIndex := opts.TotalFiles(cfg.LabelsPerUnit) - 1
-	logger.Debug("attempting to remove redundant files above index", zap.Int("maxFileIndex", maxFileIndex))
-
-	files, err := os.ReadDir(opts.DataDir)
-	if err != nil {
-		return err
-	}
-	for _, file := range files {
-		name := file.Name()
-		fileIndex, err := shared.ParseFileIndex(name)
-		if err != nil && name != MetadataFileName {
-			// TODO(mafa): revert back to warning, see https://github.com/spacemeshos/go-spacemesh/issues/4789
-			logger.Debug("found unrecognized file", zap.String("fileName", name))
-			continue
-		}
-		if fileIndex > maxFileIndex {
-			logger.Info("removing redundant file", zap.String("fileName", name))
-			path := filepath.Join(opts.DataDir, name)
-			if err := os.Remove(path); err != nil {
-				return fmt.Errorf("failed to delete file (%v): %w", path, err)
-			}
-		}
-	}
-	return nil
-}
-
 func (init *Initializer) NumLabelsWritten() uint64 {
 	return init.numLabelsWritten.Load()
 }
@@ -670,12 +637,18 @@ func (init *Initializer) verifyMetadata(m *shared.PostMetadata) error {
 	if init.opts.NumUnits > m.NumUnits {
 		return ConfigMismatchError{
 			Param:    "NumUnits",
-			Expected: fmt.Sprintf(">= %d", init.opts.NumUnits),
+			Expected: fmt.Sprintf("%d", init.opts.NumUnits),
 			Found:    fmt.Sprintf("%d", m.NumUnits),
 			DataDir:  init.opts.DataDir,
 		}
 	}
 
+	if init.opts.NumUnits < m.NumUnits {
+		init.logger.Warn("initialization: found more units than expected, did you forget to delete some files?",
+			zap.Uint32("expected", init.opts.NumUnits),
+			zap.Uint32("found", m.NumUnits))
+	}
+
 	return nil
 }
 

initialization/initialization_test.go

@@ -531,7 +531,9 @@ func TestInitialize_RedundantFiles(t *testing.T) {
 		r.NoError(err)
 		newLayout, err := deriveFilesLayout(cfg, newOpts)
 		r.NoError(err)
-		r.Equal(newLayout.NumFiles(), numFiles)
+
+		// we allow extra files
+		r.LessOrEqual(newLayout.NumFiles(), numFiles)
 		r.Less(newLayout.NumFiles(), layout.NumFiles())
 
 		cancel()
@@ -664,6 +666,7 @@ func TestValidateMetadata(t *testing.T) {
 	r := require.New(t)
 
 	cfg, opts := getTestConfig(t)
+	opts.NumUnits++
 
 	init, err := NewInitializer(
 		WithNodeId(nodeId),
@@ -735,6 +738,19 @@ func TestValidateMetadata(t *testing.T) {
 	)
 	r.ErrorAs(err, &errConfigMismatch)
 	r.Equal("NumUnits", errConfigMismatch.Param)
+
+	// Attempt to initialize with a lower `opts.NumUnits`.
+	newOpts = opts
+	newOpts.NumUnits--
+	_, err = NewInitializer(
+		WithNodeId(nodeId),
+		WithCommitmentAtxId(commitmentAtxId),
+		WithConfig(cfg),
+		WithInitOpts(newOpts),
+		WithLogger(zaptest.NewLogger(t, zaptest.Level(zap.DebugLevel))),
+	)
+	// this is allowed
+	r.NoError(err)
 }
 
 func TestStop(t *testing.T) {
@@ -1094,33 +1110,3 @@ func TestInitializeLastFileIsSmaller(t *testing.T) {
 	r.NoError(err)
 	r.Equal(cfg.UnitSize(), uint64(file.Size()))
 }
-
-func TestRemoveRedundantFiles(t *testing.T) {
-	cfg := config.DefaultConfig()
-
-	opts := config.DefaultInitOpts()
-	opts.DataDir = t.TempDir()
-	opts.NumUnits = 3
-	opts.MaxFileSize = 2 * cfg.UnitSize()
-
-	expectedFilesCount := opts.TotalFiles(cfg.LabelsPerUnit)
-	// Create 2 redundant files
-	for i := 0; i < expectedFilesCount+2; i++ {
-		f, err := os.Create(filepath.Join(opts.DataDir, shared.InitFileName(i)))
-		require.NoError(t, err)
-		_, err = f.Write([]byte("test"))
-		require.NoError(t, err)
-		require.NoError(t, f.Close())
-	}
-
-	removeRedundantFiles(cfg, opts, zap.NewNop())
-
-	files, err := os.ReadDir(opts.DataDir)
-	require.NoError(t, err)
-	require.Len(t, files, expectedFilesCount)
-
-	for i := 0; i < expectedFilesCount; i++ {
-		_, err := os.Stat(filepath.Join(opts.DataDir, shared.InitFileName(i)))
-		require.NoError(t, err)
-	}
-}