hashicorp/nomad · error

unable to create service

Error message

unable to create service - %w

What it means

Returned by serviceInstall when WindowsServiceManager.CreateService fails to register a new Nomad Windows service (the registry showed no existing one). The service could not be created with the supplied binary path and configuration.

Solutions

1. Run the install from an elevated (Administrator) shell
2. If a stale entry exists, `sc.exe delete nomad`, reboot, and retry
3. Check the chained %w cause for the exact SCM error code
4. Ensure sufficient free disk space and a valid binary path

Example fix

// before
PS> nomad windows install
unable to create service - Access is denied
// after
PS (admin)> nomad windows install

if !isAdmin() {
	log.Fatal("creating the Nomad service requires an elevated shell")
}
out, _ := exec.Command("sc.exe", "query", "nomad").CombinedOutput()
log.Printf("service pre-check: %s", out)

srvc, err = m.CreateService(winsvc.WINDOWS_SERVICE_NAME, opts.binaryPath, cfg)
if err != nil {
	if errors.Is(err, windows.ERROR_SERVICE_EXISTS) {
		// fall back to the GetService/Configure update path
	}
	return fmt.Errorf("unable to create service - %w", err)
}

When it happens

Trigger: Creating the Windows service 'Nomad' fails: ERROR_ACCESS_DENIED without elevation, service name already exists but the earlier check missed it, or disk full / invalid parameters.

Common situations: Non-elevated install attempt; leftover service entry deleted-but-pending (marked for deletion); security software blocking service creation.

Related errors

• could not get existing service
• service registration check failed
• unable to check for existing service
• cannot create configuration directory
• cannot create copy

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/2e12df44accb8120. Report an issue: GitHub.

Appendix: source

Thrown at command/windows_service_install.go:224

		if err := srvc.Configure(winsvc.WindowsServiceConfiguration{
			StartType:      winsvc.StartAutomatic,
			DisplayName:    winsvc.WINDOWS_SERVICE_DISPLAY_NAME,
			Description:    winsvc.WINDOWS_SERVICE_DESCRIPTION,
			BinaryPathName: cmd,
		}); err != nil {
			return fmt.Errorf("unable to configure service - %w", err)
		}
	} else {
		srvc, err = m.CreateService(winsvc.WINDOWS_SERVICE_NAME, opts.binaryPath,
			winsvc.WindowsServiceConfiguration{
				StartType:      winsvc.StartAutomatic,
				DisplayName:    winsvc.WINDOWS_SERVICE_DISPLAY_NAME,
				Description:    winsvc.WINDOWS_SERVICE_DESCRIPTION,
				BinaryPathName: cmd,
			},
		)
		if err != nil {
			return fmt.Errorf("unable to create service - %w", err)
		}
		defer srvc.Close()
	}

	// Enable the service in the Windows eventlog
	if err := srvc.EnableEventlog(); err != nil {
		return fmt.Errorf("could not configure eventlog - %w", err)
	}

	// Ensure the service is stopped
	if err := srvc.Stop(); err != nil {
		return fmt.Errorf("could not stop service - %w", err)
	}

	// Start the service so the new binary is in use
	if err := srvc.Start(); err != nil {
		return fmt.Errorf("could not start service - %w", err)
	}

View on GitHub (pinned to 482b49bf1a)