juicedata/juicefs · error

create external sorter: %w

Error message

create external sorter: %w

What it means

New builds a sharded external sorter for GC; if the underlying sorter library fails to construct (returned over errCh), the work directory is removed and 'create external sorter: %w' wraps the root cause. This indicates the external sort infrastructure could not be initialized, e.g. work-dir or writer failures.

Source

Thrown at pkg/utils/extsort/sharded.go:80

	input := make(chan T, cfg.Threads*128)
	sorter, _, errCh := lanratextsort.Generic(
		input,
		codec.FromBytes,
		codec.ToBytes,
		codec.Compare,
		&lanratextsort.Config{
			ChunkSize:          defaultChunkSize,
			NumWorkers:         cfg.Threads,
			ChanBuffSize:       cfg.Threads,
			SortedChanBuffSize: cfg.Threads * 32,
			TempFilesDir:       workDir,
			Checksum:           cfg.Checksum,
		},
	)
	if sorter == nil {
		err := <-errCh
		_ = os.RemoveAll(workDir)
		return nil, fmt.Errorf("create external sorter: %w", err)
	}
	s := &Sorter[T]{input: input, sorter: sorter, errCh: errCh, workDir: workDir}
	go sorter.Sort(ctx)
	return s, nil
}

func (s *Sorter[T]) Input() chan<- T {
	return s.input
}

func (s *Sorter[T]) CloseInput() {
	close(s.input)
}

func (s *Sorter[T]) Next(ctx context.Context) (T, bool, error) {
	return s.sorter.Next(ctx)
}

View on GitHub (pinned to c9a67b23e8)

Solutions

1. Read the wrapped root cause (%w) for the actual failure
2. Ensure the work/temp directory exists and is writable with sufficient space
3. Set TMPDIR to a larger writable location
4. Re-run GC after freeing disk space

if st, err := os.Stat(workDirParent); err != nil || !st.IsDir() || unix.Access(workDirParent, unix.W_OK) != nil { fail early }

sorter, err := New(...); if err != nil { return fmt.Errorf("gc sorter init: %w", err) } // inspect %w cause

When it happens

Trigger: Calling New (via newGcExternalSorters during GC) when the sorter constructor fails — typically the temp/work directory cannot be created or the sorter factory returns an error.

Common situations: No space or permissions in the temp directory (TMPDIR misconfigured, read-only FS); excessive memory/disk limits in containers blocking sorter spawn.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• space not enough on device
• invalid value for delayed slices %q: %v
• scan trash slices: %s
• list all blocks: %s
• list chunks from %s: %s

AI-assisted analysis of juicedata/juicefs@c9a67b23e8 (2026-09-06). Data as JSON: /api/errors/06f1c5b80ab0d1fa. Report an issue: GitHub.