What causes "file already at maximum size (%d bytes)" in wavetermdev/waveterm?

Stop appending and rotate the file: write to a new file name instead

file already at maximum size (%d bytes)

Error message

file already at maximum size (%d bytes)

What it means

wsh file append refuses to start when the remote file already has size >= MaxFileSize (10MB). The append command enforces the same hard cap as file write, so once a file reaches the cap no more data may be appended. The check uses FileInfo returned by ensureFile before any data is read from stdin.

Source

Thrown at cmd/wsh/cmd/wshcmd-file.go:281

	return nil
}

func fileAppendRun(cmd *cobra.Command, args []string) error {
	path, err := fixRelativePaths(args[0])
	if err != nil {
		return err
	}
	fileData := wshrpc.FileData{
		Info: &wshrpc.FileInfo{
			Path: path}}

	info, err := ensureFile(fileData)
	if err != nil {
		return err
	}
	if info.Size >= MaxFileSize {
		return fmt.Errorf("file already at maximum size (%d bytes)", MaxFileSize)
	}

	reader := bufio.NewReader(WrappedStdin)
	var buf bytes.Buffer
	remainingSpace := MaxFileSize - info.Size
	for {
		chunk := make([]byte, 8192)
		n, err := reader.Read(chunk)
		if err == io.EOF {
			break
		}
		if err != nil {
			return fmt.Errorf("reading input: %w", err)
		}

		if int64(buf.Len()+n) > remainingSpace {
			return fmt.Errorf("append would exceed maximum file size of %d bytes", MaxFileSize)
		}

View on GitHub (pinned to a4447c1563)

Solutions

Stop appending and rotate the file: write to a new file name instead
Truncate or remove the remote file if the old content is no longer needed ('wsh file write' with empty input or rm)
Split the data across multiple files under 10MB each

Example fix

// before
wsh file append [block] app.log < stream.log   # fails: file already at maximum size
// after
wsh file write [block] app-2026-09.log < stream.log  # rotate to a new file

Defensive patterns

Strategy: validation

Validate before calling

info, err := wshclient.FileInfoCommand(RpcClient, wshrpc.CommandFileData{Info: &wshrpc.FileInfo{Path: path}}, &wshrpc.RpcOpts{Timeout: fileTimeout})
if err == nil && info.Size >= 10*1024*1024 {
    return fmt.Errorf("cannot append: %s already at %d bytes", path, info.Size)
}

Type guard

func fileAtCap(info *wshrpc.FileInfo) bool {
    return info != nil && info.Size >= 10*1024*1024
}

Prevention

Check remote file size before long-running append jobs
Rotate log/data files before they reach 10MB
Monitor append targets with periodic 'wsh file info' calls

When it happens

Trigger: Running 'wsh file append [block] <path>' when ensureFile reports info.Size >= 10485760 bytes for the target file.

Common situations: Repeatedly appending log output to the same remote file until it hits the 10MB cap; piping an ongoing stream into an already-full file.

Understand the failure class

Background: "File too large" / "file size exceeds limit" errors: why libraries cap file sizes and how to fix them — this error's family across 46 libraries.

Related errors

AI-assisted analysis of wavetermdev/waveterm@a4447c1563 (2026-09-01). Data as JSON: /api/errors/23e2d912ba1ec76b. Report an issue: GitHub.