hashicorp/nomad · error

device %d failed validation: %v

Error message

device %d failed validation: %v

What it means

Resources.Validate iterates the task's device blocks and prefixes each device's own validation failure with its 1-based position. The underlying cause is reported by DeviceGroup.Validate (bad name, invalid attribute, etc.) for that indexed device request.

Source

Thrown at nomad/structs/structs.go:2444

	if r.Cores < 0 {
		mErr.Errors = append(mErr.Errors, fmt.Errorf("cores value (%d) cannot be negative", r.Cores))
	}

	if err := r.MeetsMinResources(); err != nil {
		mErr.Errors = append(mErr.Errors, err)
	}

	// Ensure the task isn't asking for disk resources
	if r.DiskMB > 0 {
		mErr.Errors = append(mErr.Errors, errors.New("Task can't ask for disk resources, they have to be specified at the task group level."))
	}

	// Ensure devices are valid
	devices := set.New[string](len(r.Devices))
	for i, d := range r.Devices {
		if err := d.Validate(); err != nil {
			mErr.Errors = append(mErr.Errors, fmt.Errorf("device %d failed validation: %v", i+1, err))
		}
		devices.Insert(d.Name)
	}

	// Ensure each numa bound device matches a device requested for task
	if r.NUMA != nil {
		for _, numaDevice := range r.NUMA.Devices {
			if !devices.Contains(numaDevice) {
				mErr.Errors = append(mErr.Errors, fmt.Errorf("numa device %q not requested as task resource", numaDevice))
			}
		}
	}

	// Ensure the numa block is valid
	if err := r.NUMA.Validate(); err != nil {
		mErr.Errors = append(mErr.Errors, err)
	}

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Inspect the wrapped error for the offending device block and fix its fields (name, count, constraints, attributes)

When it happens

Trigger: Thrown at nomad/structs/structs.go:2444 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/5967fdf273c8e033. Report an issue: GitHub.