What causes "failed to get free disk space for %s: %v" in hashicorp/nomad?

Verify the volume path exists and is mounted (dir or Get-PSDrive in PowerShell)

failed to get free disk space for %s: %v

Error message

failed to get free disk space for %s: %v

What it means

diskInfo() calls getDiskSpaceEx (a wrapper around GetDiskFreeSpaceEx) to read the total bytes of the volume. If the Windows API call fails, this error wraps the OS reason. Commonly the volume does not exist, is not mounted, or the process lacks permission to query it.

Source

Thrown at client/fingerprint/storage_windows.go:32

//sys	getDiskSpaceEx(dirName *uint16, availableFreeBytes *uint64, totalBytes *uint64, totalFreeBytes *uint64) (err error) = kernel32.GetDiskFreeSpaceExW

// diskInfo inspects the filesystem for path and returns the volume name and
// the total bytes available on the file system.
func (f *StorageFingerprint) diskInfo(path string) (volume string, total uint64, err error) {
	absPath, err := filepath.Abs(path)
	if err != nil {
		return "", 0, fmt.Errorf("failed to determine absolute path for %s", path)
	}

	volume = filepath.VolumeName(absPath)

	absPathp, err := syscall.UTF16PtrFromString(absPath)
	if err != nil {
		return "", 0, fmt.Errorf("failed to convert \"%s\" to UTF16: %v", absPath, err)
	}

	if err := getDiskSpaceEx(absPathp, nil, &total, nil); err != nil {
		return "", 0, fmt.Errorf("failed to get free disk space for %s: %v", absPath, err)
	}

	return volume, total, nil
}

View on GitHub (pinned to 482b49bf1a)

Solutions

Verify the volume path exists and is mounted (dir <path> or Get-PSDrive in PowerShell)
If it's a network drive, restore connectivity or use a local volume in the fingerprint paths
Grant the Nomad client's service account permission to query the volume
Unlock/repair the volume (BitLocker, chkdsk) if the underlying error indicates a filesystem problem

Example fix

// before (client config)
fingerprint {
  storage { 
  }
} // client erroring on "E:\"
// after
# ensure only mounted volumes are presented, or fix the host:
New-Partition -DiskNumber 1 -DriveLetter E | Format-Volume

Defensive patterns

Strategy: try-catch

Validate before calling

if fi, err := os.Stat(path); err != nil || !fi.IsDir() {
    return fmt.Errorf("volume path %s is not accessible on this host", path)
}

Type guard

func isQueryableVolume(p string) bool {
    _, err := os.Stat(filepath.VolumeName(mustAbs(p)) + "\\")
    return err == nil
}

Try / catch

volume, total, err := fp.diskInfo(path)
if err != nil {
    var se syscall.Errno
    if errors.As(err, &se) && (errors.Is(err, os.ErrNotExist) || se == syscall.ERROR_ACCESS_DENIED) {
        log.Printf("volume %s unavailable: %v", path, err)
        return nil
    }
    return err
}

Prevention

Ensure all drive letters referenced by the client config are mounted (check with Get-PSDrive)
Run the Nomad service under an account with rights to query target volumes
Avoid fingerprinting disconnected network shares; verify connectivity first
Keep volumes unlocked (BitLocker) and healthy (periodic chkdsk)

When it happens

Trigger: Storage fingerprint on Windows where getDiskSpaceEx returns a nonzero error — e.g. the drive letter/volume is absent, a mapped network drive is unreachable, or access is denied.

Common situations: Client config references a drive letter that isn't mounted (E:\ on a host with only C:); disconnected SMB/network share; removable drive unplugged; BitLocker-locked volume; insufficient privileges for the Nomad service account.

Related errors

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/4fa64c641110b63d. Report an issue: GitHub.