diff --git a/cpp/controllers/scsi_controller.cpp b/cpp/controllers/scsi_controller.cpp
index e6d1f45c6b..26bb553ed8 100644
--- a/cpp/controllers/scsi_controller.cpp
+++ b/cpp/controllers/scsi_controller.cpp
@@ -411,8 +411,8 @@ void ScsiController::Error(sense_key sense_key, asc asc, status status)
 
 	if (sense_key != sense_key::no_sense || asc != asc::no_additional_sense_information) {
 		stringstream s;
-		s << setfill('0') << setw(2) << hex << "Error status: Sense Key $" << static_cast<int>(sense_key)
-				<< ", ASC $" << static_cast<int>(asc);
+		s << setfill('0') << hex << "Error status: Sense Key $" << setw(2) << static_cast<int>(sense_key)
+				<< ", ASC $" << setw(2) << static_cast<int>(asc);
 		LogDebug(s.str());
 
 		// Set Sense Key and ASC for a subsequent REQUEST SENSE
@@ -422,8 +422,6 @@ void ScsiController::Error(sense_key sense_key, asc asc, status status)
 	SetStatus(status);
 	SetMessage(0x00);
 
-	LogTrace("Error (to status phase)");
-
 	Status();
 }
 
@@ -478,24 +476,19 @@ void ScsiController::Send()
 		case phase_t::msgin:
 			// Completed sending response to extended message of IDENTIFY message
 			if (scsi.atnmsg) {
-				// flag off
 				scsi.atnmsg = false;
 
-				// command phase
 				Command();
 			} else {
-				// Bus free phase
 				BusFree();
 			}
 			break;
 
 		case phase_t::datain:
-			// status phase
 			Status();
 			break;
 
 		case phase_t::status:
-			// Message in phase
 			SetLength(1);
 			SetBlocks(1);
 			GetBuffer()[0] = (uint8_t)GetMessage();
diff --git a/cpp/piscsi/command_context.cpp b/cpp/piscsi/command_context.cpp
index 5b381d9f43..ab4eeac402 100644
--- a/cpp/piscsi/command_context.cpp
+++ b/cpp/piscsi/command_context.cpp
@@ -43,10 +43,11 @@ void CommandContext::WriteResult(const PbResult& result) const
 	}
 }
 
-void CommandContext::WriteSuccessResult(PbResult& result) const
+bool CommandContext::WriteSuccessResult(PbResult& result) const
 {
 	result.set_status(true);
 	WriteResult(result);
+	return true;
 }
 
 bool CommandContext::ReturnLocalizedError(LocalizationKey key, const string& arg1, const string& arg2,
@@ -59,7 +60,13 @@ bool CommandContext::ReturnLocalizedError(LocalizationKey key, PbErrorCode error
 		const string& arg2, const string& arg3) const
 {
 	// For the logfile always use English
-	spdlog::error(localizer.Localize(key, "en", arg1, arg2, arg3));
+	// Do not log unknown operations as an error for backward/foward compatibility with old/new clients
+	if (error_code == PbErrorCode::UNKNOWN_OPERATION) {
+		spdlog::trace(localizer.Localize(key, "en", arg1, arg2, arg3));
+	}
+	else {
+		spdlog::error(localizer.Localize(key, "en", arg1, arg2, arg3));
+	}
 
 	return ReturnStatus(false, localizer.Localize(key, locale, arg1, arg2, arg3), error_code, false);
 }
diff --git a/cpp/piscsi/command_context.h b/cpp/piscsi/command_context.h
index dcbb2d2003..25c4dbb84d 100644
--- a/cpp/piscsi/command_context.h
+++ b/cpp/piscsi/command_context.h
@@ -29,7 +29,7 @@ class CommandContext
 	void SetDefaultFolder(string_view f) { default_folder = f; }
 	bool ReadCommand();
 	void WriteResult(const PbResult&) const;
-	void WriteSuccessResult(PbResult&) const;
+	bool WriteSuccessResult(PbResult&) const;
 	const PbCommand& GetCommand() const { return command; }
 
 	bool ReturnLocalizedError(LocalizationKey, const string& = "", const string& = "", const string& = "") const;
diff --git a/cpp/piscsi/localizer.cpp b/cpp/piscsi/localizer.cpp
index 17c92034aa..1ac8f5f7fc 100644
--- a/cpp/piscsi/localizer.cpp
+++ b/cpp/piscsi/localizer.cpp
@@ -22,12 +22,12 @@ Localizer::Localizer()
 	Add(LocalizationKey::ERROR_AUTHENTICATION, "es", "Fallo de autentificación");
 	Add(LocalizationKey::ERROR_AUTHENTICATION, "zh", "认证失败");
 
-	Add(LocalizationKey::ERROR_OPERATION, "en", "Unknown operation");
-	Add(LocalizationKey::ERROR_OPERATION, "de", "Unbekannte Operation");
-	Add(LocalizationKey::ERROR_OPERATION, "sv", "Okänd operation");
-	Add(LocalizationKey::ERROR_OPERATION, "fr", "Opération inconnue");
-	Add(LocalizationKey::ERROR_OPERATION, "es", "Operación desconocida");
-	Add(LocalizationKey::ERROR_OPERATION, "zh", "未知操作");
+	Add(LocalizationKey::ERROR_OPERATION, "en", "Unknown operation: %1");
+	Add(LocalizationKey::ERROR_OPERATION, "de", "Unbekannte Operation: %1");
+	Add(LocalizationKey::ERROR_OPERATION, "sv", "Okänd operation: %1");
+	Add(LocalizationKey::ERROR_OPERATION, "fr", "Opération inconnue: %1");
+	Add(LocalizationKey::ERROR_OPERATION, "es", "Operación desconocida: %1");
+	Add(LocalizationKey::ERROR_OPERATION, "zh", "未知操作: %1");
 
 	Add(LocalizationKey::ERROR_LOG_LEVEL, "en", "Invalid log level '%1'");
 	Add(LocalizationKey::ERROR_LOG_LEVEL, "de", "Ungültiger Log-Level '%1'");
diff --git a/cpp/piscsi/piscsi_core.cpp b/cpp/piscsi/piscsi_core.cpp
index 1be72793cd..553e229707 100644
--- a/cpp/piscsi/piscsi_core.cpp
+++ b/cpp/piscsi/piscsi_core.cpp
@@ -33,6 +33,7 @@
 
 using namespace std;
 using namespace filesystem;
+using namespace spdlog;
 using namespace piscsi_interface;
 using namespace piscsi_util;
 using namespace protobuf_util;
@@ -71,7 +72,7 @@ bool Piscsi::InitBus()
 		return false;
 	}
 
-	executor = make_unique<PiscsiExecutor>(piscsi_image, *bus, controller_manager);
+	executor = make_unique<PiscsiExecutor>(*bus, controller_manager);
 
 	return true;
 }
@@ -84,7 +85,12 @@ void Piscsi::CleanUp()
 
 	executor->DetachAll();
 
-	bus->Cleanup();
+	// TODO Check why there are rare cases where bus is NULL on a remote interface shutdown
+	// even though it is never set to NULL anywhere
+	assert(bus);
+	if (bus) {
+		bus->Cleanup();
+	}
 }
 
 void Piscsi::ReadAccessToken(const path& filename)
@@ -307,27 +313,26 @@ bool Piscsi::SetLogLevel(const string& log_level) const
 	return true;
 }
 
-bool Piscsi::ExecuteCommand(CommandContext& context)
+bool Piscsi::ExecuteCommand(const CommandContext& context)
 {
-	context.SetDefaultFolder(piscsi_image.GetDefaultFolder());
-
 	const PbCommand& command = context.GetCommand();
+	const PbOperation operation = command.operation();
 
 	if (!access_token.empty() && access_token != GetParam(command, "token")) {
 		return context.ReturnLocalizedError(LocalizationKey::ERROR_AUTHENTICATION, UNAUTHORIZED);
 	}
 
-	if (!PbOperation_IsValid(command.operation())) {
-		spdlog::error("Received unknown command with operation opcode " + to_string(command.operation()));
+	if (!PbOperation_IsValid(operation)) {
+		spdlog::trace("Ignored unknown command with operation opcode " + to_string(operation));
 
-		return context.ReturnLocalizedError(LocalizationKey::ERROR_OPERATION, UNKNOWN_OPERATION);
+		return context.ReturnLocalizedError(LocalizationKey::ERROR_OPERATION, UNKNOWN_OPERATION, to_string(operation));
 	}
 
-	spdlog::trace("Received " + PbOperation_Name(command.operation()) + " command");
+	spdlog::trace("Received " + PbOperation_Name(operation) + " command");
 
 	PbResult result;
 
-	switch(command.operation()) {
+	switch(operation) {
 		case LOG_LEVEL:
 			if (const string log_level = GetParam(command, "level"); !SetLogLevel(log_level)) {
 				context.ReturnLocalizedError(LocalizationKey::ERROR_LOG_LEVEL, log_level);
@@ -353,8 +358,7 @@ bool Piscsi::ExecuteCommand(CommandContext& context)
 
 		case DEVICE_TYPES_INFO:
 			response.GetDeviceTypesInfo(*result.mutable_device_types_info());
-			context.WriteSuccessResult(result);
-			break;
+			return context.WriteSuccessResult(result);
 
 		case SERVER_INFO:
 			response.GetServerInfo(*result.mutable_server_info(), command, controller_manager.GetAllDevices(),
@@ -364,19 +368,16 @@ bool Piscsi::ExecuteCommand(CommandContext& context)
 
 		case VERSION_INFO:
 			response.GetVersionInfo(*result.mutable_version_info());
-			context.WriteSuccessResult(result);
-			break;
+			return context.WriteSuccessResult(result);
 
 		case LOG_LEVEL_INFO:
 			response.GetLogLevelInfo(*result.mutable_log_level_info());
-			context.WriteSuccessResult(result);
-			break;
+			return context.WriteSuccessResult(result);
 
 		case DEFAULT_IMAGE_FILES_INFO:
 			response.GetImageFilesInfo(*result.mutable_image_files_info(), piscsi_image.GetDefaultFolder(),
 					GetParam(command, "folder_pattern"), GetParam(command, "file_pattern"), piscsi_image.GetDepth());
-			context.WriteSuccessResult(result);
-			break;
+			return context.WriteSuccessResult(result);
 
 		case IMAGE_FILE_INFO:
 			if (string filename = GetParam(command, "file"); filename.empty()) {
@@ -399,13 +400,11 @@ bool Piscsi::ExecuteCommand(CommandContext& context)
 
 		case NETWORK_INTERFACES_INFO:
 			response.GetNetworkInterfacesInfo(*result.mutable_network_interfaces_info());
-			context.WriteSuccessResult(result);
-			break;
+			return context.WriteSuccessResult(result);
 
 		case MAPPING_INFO:
 			response.GetMappingInfo(*result.mutable_mapping_info());
-			context.WriteSuccessResult(result);
-			break;
+			return context.WriteSuccessResult(result);
 
 		case STATISTICS_INFO:
 			response.GetStatisticsInfo(*result.mutable_statistics_info(), controller_manager.GetAllDevices());
@@ -414,45 +413,65 @@ bool Piscsi::ExecuteCommand(CommandContext& context)
 
 		case OPERATION_INFO:
 			response.GetOperationInfo(*result.mutable_operation_info(), piscsi_image.GetDepth());
-			context.WriteSuccessResult(result);
-			break;
+			return context.WriteSuccessResult(result);
 
 		case RESERVED_IDS_INFO:
 			response.GetReservedIds(*result.mutable_reserved_ids_info(), executor->GetReservedIds());
-			context.WriteSuccessResult(result);
-			break;
+			return context.WriteSuccessResult(result);
 
 		case SHUT_DOWN:
-			if (executor->ShutDown(context, GetParam(command, "mode"))) {
-				TerminationHandler(0);
-			}
-			break;
+			return ShutDown(context, GetParam(command, "mode"));
 
 		case NO_OPERATION:
-			context.ReturnSuccessStatus();
-			break;
+			return context.ReturnSuccessStatus();
 
-		// TODO The image operations below can most likely directly be executed without calling the executor,
-		// because they do not require the target to be idle
 		case CREATE_IMAGE:
+			return piscsi_image.CreateImage(context);
+
 		case DELETE_IMAGE:
+			return piscsi_image.DeleteImage(context);
+
 		case RENAME_IMAGE:
+			return piscsi_image.RenameImage(context);
+
 		case COPY_IMAGE:
+			return piscsi_image.CopyImage(context);
+
 		case PROTECT_IMAGE:
 		case UNPROTECT_IMAGE:
+			return piscsi_image.SetImagePermissions(context);
+
 		case RESERVE_IDS:
 			return executor->ProcessCmd(context);
 
-		// The remaining commands can only be executed when the target is idle
-		// TODO What happens when the target becomes active while the command is still being executed?
-		// A field 'mutex locker' can probably avoid SCSI commands and ProcessCmd() being executed at the same time
 		default:
-			// TODO Find a better way to wait
-			const timespec ts = { .tv_sec = 0, .tv_nsec = 500'000'000};
-			while (target_is_active) {
-				nanosleep(&ts, nullptr);
+			// The remaining commands may only be executed when the target is idle
+			if (!ExecuteWithLock(context)) {
+				return false;
 			}
-			return executor->ProcessCmd(context);
+
+			return HandleDeviceListChange(context, operation);
+	}
+
+	return true;
+}
+
+bool Piscsi::ExecuteWithLock(const CommandContext& context)
+{
+	scoped_lock<mutex> lock(execution_locker);
+	return executor->ProcessCmd(context);
+}
+
+bool Piscsi::HandleDeviceListChange(const CommandContext& context, PbOperation operation) const
+{
+	// ATTACH and DETACH return the resulting device list
+	if (operation == ATTACH || operation == DETACH) {
+		// A command with an empty device list is required here in order to return data for all devices
+		PbCommand command;
+		PbResult result;
+		response.GetDevicesInfo(controller_manager.GetAllDevices(), result, command, piscsi_image.GetDefaultFolder());
+		context.WriteResult(result);
+		return result.status();
 	}
 
 	return true;
@@ -489,8 +508,10 @@ int Piscsi::run(span<char *> args)
 		return EXIT_FAILURE;
 	}
 
-	if (const string error = service.Init([this] (CommandContext& context) { return ExecuteCommand(context); }, port);
-		!error.empty()) {
+	if (const string error = service.Init([this] (CommandContext& context) {
+			context.SetDefaultFolder(piscsi_image.GetDefaultFolder());
+			return ExecuteCommand(context);
+		}, port); !error.empty()) {
 		cerr << "Error: " << error << endl;
 
 		CleanUp();
@@ -584,7 +605,7 @@ void Piscsi::Process()
 
 		// Only process the SCSI command if the bus is not busy and no other device responded
 		if (IsNotBusy() && bus->GetSEL()) {
-			target_is_active = true;
+			scoped_lock<mutex> lock(execution_locker);
 
 			// Process command on the responsible controller based on the current initiator and target ID
 			if (const auto shutdown_mode = controller_manager.ProcessOnController(bus->GetDAT());
@@ -592,23 +613,54 @@ void Piscsi::Process()
 				// When the bus is free PiSCSI or the Pi may be shut down.
 				ShutDown(shutdown_mode);
 			}
-
-			target_is_active = false;
 		}
 	}
 }
 
-void Piscsi::ShutDown(AbstractController::piscsi_shutdown_mode shutdown_mode)
-{
-	CleanUp();
+// Shutdown on a remote interface command
+bool Piscsi::ShutDown(const CommandContext& context, const string& m) {
+	if (m.empty()) {
+		return context.ReturnLocalizedError(LocalizationKey::ERROR_SHUTDOWN_MODE_MISSING);
+	}
 
+	AbstractController::piscsi_shutdown_mode mode = AbstractController::piscsi_shutdown_mode::NONE;
+	if (m == "rascsi") {
+		mode = AbstractController::piscsi_shutdown_mode::STOP_PISCSI;
+	}
+	else if (m == "system") {
+		mode = AbstractController::piscsi_shutdown_mode::STOP_PI;
+	}
+	else if (m == "reboot") {
+		mode = AbstractController::piscsi_shutdown_mode::RESTART_PI;
+	}
+	else {
+		return context.ReturnLocalizedError(LocalizationKey::ERROR_SHUTDOWN_MODE_INVALID, m);
+	}
+
+	// Shutdown modes other than rascsi require root permissions
+	if (mode != AbstractController::piscsi_shutdown_mode::STOP_PISCSI && getuid()) {
+		return context.ReturnLocalizedError(LocalizationKey::ERROR_SHUTDOWN_PERMISSION);
+	}
+
+	// Report success now because after a shutdown nothing can be reported anymore
+	PbResult result;
+	context.WriteSuccessResult(result);
+
+	return ShutDown(mode);
+}
+
+// Shutdown on a SCSI command
+bool Piscsi::ShutDown(AbstractController::piscsi_shutdown_mode shutdown_mode)
+{
 	switch(shutdown_mode) {
 	case AbstractController::piscsi_shutdown_mode::STOP_PISCSI:
 		spdlog::info("PiSCSI shutdown requested");
-		break;
+		CleanUp();
+		return true;
 
 	case AbstractController::piscsi_shutdown_mode::STOP_PI:
 		spdlog::info("Raspberry Pi shutdown requested");
+		CleanUp();
 		if (system("init 0") == -1) {
 			spdlog::error("Raspberry Pi shutdown failed");
 		}
@@ -616,6 +668,7 @@ void Piscsi::ShutDown(AbstractController::piscsi_shutdown_mode shutdown_mode)
 
 	case AbstractController::piscsi_shutdown_mode::RESTART_PI:
 		spdlog::info("Raspberry Pi restart requested");
+		CleanUp();
 		if (system("init 6") == -1) {
 			spdlog::error("Raspberry Pi restart failed");
 		}
@@ -625,6 +678,8 @@ void Piscsi::ShutDown(AbstractController::piscsi_shutdown_mode shutdown_mode)
 		assert(false);
 		break;
 	}
+
+	return false;
 }
 
 bool Piscsi::IsNotBusy() const
diff --git a/cpp/piscsi/piscsi_core.h b/cpp/piscsi/piscsi_core.h
index fea8dd73da..1560851d41 100644
--- a/cpp/piscsi/piscsi_core.h
+++ b/cpp/piscsi/piscsi_core.h
@@ -10,7 +10,6 @@
 #pragma once
 
 #include "controllers/controller_manager.h"
-#include "controllers/abstract_controller.h"
 #include "piscsi/command_context.h"
 #include "piscsi/piscsi_service.h"
 #include "piscsi/piscsi_image.h"
@@ -20,7 +19,7 @@
 #include "spdlog/sinks/stdout_color_sinks.h"
 #include <span>
 #include <string>
-#include <atomic>
+#include <mutex>
 
 using namespace std;
 
@@ -49,9 +48,12 @@ class Piscsi
 	void Process();
 	bool IsNotBusy() const;
 
-	void ShutDown(AbstractController::piscsi_shutdown_mode);
+	bool ShutDown(AbstractController::piscsi_shutdown_mode);
+	bool ShutDown(const CommandContext&, const string&);
 
-	bool ExecuteCommand(CommandContext&);
+	bool ExecuteCommand(const CommandContext&);
+	bool ExecuteWithLock(const CommandContext&);
+	bool HandleDeviceListChange(const CommandContext&, PbOperation) const;
 
 	bool SetLogLevel(const string&) const;
 
@@ -59,8 +61,7 @@ class Piscsi
 
 	static PbDeviceType ParseDeviceType(const string&);
 
-	// Processing flag
-	atomic_bool target_is_active;
+	mutex execution_locker;
 
 	string access_token;
 
diff --git a/cpp/piscsi/piscsi_executor.cpp b/cpp/piscsi/piscsi_executor.cpp
index c5564e0132..fcb43db8e0 100644
--- a/cpp/piscsi/piscsi_executor.cpp
+++ b/cpp/piscsi/piscsi_executor.cpp
@@ -10,11 +10,8 @@
 #include "shared/piscsi_util.h"
 #include "shared/protobuf_util.h"
 #include "shared/piscsi_exceptions.h"
-#include "controllers/scsi_controller.h"
 #include "devices/device_factory.h"
-#include "devices/primary_device.h"
 #include "devices/disk.h"
-#include "piscsi_image.h"
 #include "localizer.h"
 #include "command_context.h"
 #include "piscsi_executor.h"
@@ -82,7 +79,7 @@ bool PiscsiExecutor::ProcessDeviceCmd(const CommandContext& context, const PbDev
 			break;
 
 		default:
-			return context.ReturnLocalizedError(LocalizationKey::ERROR_OPERATION);
+			return context.ReturnLocalizedError(LocalizationKey::ERROR_OPERATION, to_string(operation));
 	}
 
 	return true;
@@ -92,36 +89,20 @@ bool PiscsiExecutor::ProcessCmd(const CommandContext& context)
 {
 	const PbCommand& command = context.GetCommand();
 
+	// Handle commands that are not device-specific
 	switch (command.operation()) {
 		case DETACH_ALL:
 			DetachAll();
 			return context.ReturnSuccessStatus();
 
 		case RESERVE_IDS: {
-			const string ids = GetParam(command, "ids");
-			if (const string error = SetReservedIds(ids); !error.empty()) {
+			if (const string error = SetReservedIds(GetParam(command, "ids")); !error.empty()) {
 				return context.ReturnErrorStatus(error);
 			}
 
 			return context.ReturnSuccessStatus();
 		}
 
-		case CREATE_IMAGE:
-			return piscsi_image.CreateImage(context);
-
-		case DELETE_IMAGE:
-			return piscsi_image.DeleteImage(context);
-
-		case RENAME_IMAGE:
-			return piscsi_image.RenameImage(context);
-
-		case COPY_IMAGE:
-			return piscsi_image.CopyImage(context);
-
-		case PROTECT_IMAGE:
-		case UNPROTECT_IMAGE:
-			return piscsi_image.SetImagePermissions(context);
-
 		default:
 			// This is a device-specific command handled below
 			break;
@@ -129,10 +110,11 @@ bool PiscsiExecutor::ProcessCmd(const CommandContext& context)
 
 	// Remember the list of reserved files during the dry run
 	const auto& reserved_files = StorageDevice::GetReservedFiles();
-	const bool reserved = ranges::find_if_not(context.GetCommand().devices(), [&] (const auto& device)
+	const bool isDryRunError = ranges::find_if_not(command.devices(), [&] (const auto& device)
 			{ return ProcessDeviceCmd(context, device, true); }) != command.devices().end();
 	StorageDevice::SetReservedFiles(reserved_files);
-	if (reserved) {
+
+	if (isDryRunError) {
 		return false;
 	}
 
@@ -145,16 +127,6 @@ bool PiscsiExecutor::ProcessCmd(const CommandContext& context)
 		return false;
 	}
 
-	// ATTACH and DETACH return the device list
-	if (command.operation() == ATTACH || command.operation() == DETACH) {
-		// A new command with an empty device list is required here in order to return data for all devices
-		PbCommand cmd;
-		PbResult result;
-		piscsi_response.GetDevicesInfo(controller_manager.GetAllDevices(), result, cmd, context.GetDefaultFolder());
-		context.WriteResult(result);
-		return true;
-	}
-
 	return context.ReturnSuccessStatus();
 }
 
@@ -336,12 +308,11 @@ bool PiscsiExecutor::Insert(const CommandContext& context, const PbDeviceDefinit
 	spdlog::info("Insert " + string(pb_device.protected_() ? "protected " : "") + "file '" + filename +
 			"' requested into " + device->GetIdentifier());
 
-	// TODO It may be better to add PrimaryDevice::Insert for all device-specific insert operations
-	auto storage_device = dynamic_pointer_cast<StorageDevice>(device);
-	if (!SetSectorSize(context, storage_device, pb_device.block_size())) {
+	if (!SetSectorSize(context, device, pb_device.block_size())) {
 		return false;
 	}
 
+	auto storage_device = dynamic_pointer_cast<StorageDevice>(device);
 	if (!ValidateImageFile(context, *storage_device, filename)) {
 		return false;
 	}
@@ -391,57 +362,6 @@ void PiscsiExecutor::DetachAll()
 	spdlog::info("Detached all devices");
 }
 
-bool PiscsiExecutor::ShutDown(const CommandContext& context, const string& mode) {
-	if (mode.empty()) {
-		return context.ReturnLocalizedError(LocalizationKey::ERROR_SHUTDOWN_MODE_MISSING);
-	}
-
-	PbResult result;
-	result.set_status(true);
-
-	// The PiSCSI shutdown mode is "rascsi" instead of "piscsi" for backwards compatibility
-	if (mode == "rascsi") {
-		spdlog::info("PiSCSI shutdown requested");
-
-		context.WriteResult(result);
-
-		return true;
-	}
-
-	if (mode != "system" && mode != "reboot") {
-		return context.ReturnLocalizedError(LocalizationKey::ERROR_SHUTDOWN_MODE_INVALID, mode);
-	}
-
-	// The root user has UID 0
-	if (getuid()) {
-		return context.ReturnLocalizedError(LocalizationKey::ERROR_SHUTDOWN_PERMISSION);
-	}
-
-	if (mode == "system") {
-		spdlog::info("System shutdown requested");
-
-		DetachAll();
-
-		context.WriteResult(result);
-
-		if (system("init 0") == -1) {
-			spdlog::error("System shutdown failed");
-		}
-	}
-	else if (mode == "reboot") {
-		spdlog::info("System reboot requested");
-
-		DetachAll();
-
-		context.WriteResult(result);
-
-		if (system("init 6") == -1) {
-			spdlog::error("System reboot failed");
-		}
-	}
-
-	return false;
-}
 
 string PiscsiExecutor::SetReservedIds(string_view ids)
 {
diff --git a/cpp/piscsi/piscsi_executor.h b/cpp/piscsi/piscsi_executor.h
index efa5916e4a..bae4fe60e3 100644
--- a/cpp/piscsi/piscsi_executor.h
+++ b/cpp/piscsi/piscsi_executor.h
@@ -11,25 +11,22 @@
 
 #include "hal/bus.h"
 #include "controllers/controller_manager.h"
-#include "piscsi/piscsi_response.h"
 #include <unordered_set>
 
-class PiscsiImage;
 class DeviceFactory;
 class PrimaryDevice;
 class StorageDevice;
 class CommandContext;
 
-using namespace spdlog;
-
 class PiscsiExecutor
 {
 public:
 
-	PiscsiExecutor(PiscsiImage& piscsi_image, BUS& bus, ControllerManager& controller_manager)
-		: piscsi_image(piscsi_image), bus(bus), controller_manager(controller_manager) {}
+	PiscsiExecutor(BUS& bus, ControllerManager& controller_manager) : bus(bus), controller_manager(controller_manager) {}
 	~PiscsiExecutor() = default;
 
+	// TODO At least some of these methods should be private, currently they are directly called by the unit tests
+
 	auto GetReservedIds() const { return reserved_ids; }
 
 	bool ProcessDeviceCmd(const CommandContext&, const PbDeviceDefinition&, bool);
@@ -43,7 +40,6 @@ class PiscsiExecutor
 	bool Insert(const CommandContext&, const PbDeviceDefinition&, const shared_ptr<PrimaryDevice>&, bool) const;
 	bool Detach(const CommandContext&, PrimaryDevice&, bool);
 	void DetachAll();
-	bool ShutDown(const CommandContext&, const string&);
 	string SetReservedIds(string_view);
 	bool ValidateImageFile(const CommandContext&, StorageDevice&, const string&) const;
 	string PrintCommand(const PbCommand&, const PbDeviceDefinition&) const;
@@ -60,10 +56,6 @@ class PiscsiExecutor
 
 	static bool CheckForReservedFile(const CommandContext&, const string&);
 
-	const PiscsiResponse piscsi_response;
-
-	PiscsiImage& piscsi_image;
-
 	BUS& bus;
 
 	ControllerManager& controller_manager;
diff --git a/cpp/piscsi/piscsi_image.cpp b/cpp/piscsi/piscsi_image.cpp
index 4c7dcc42b8..8e569e041d 100644
--- a/cpp/piscsi/piscsi_image.cpp
+++ b/cpp/piscsi/piscsi_image.cpp
@@ -276,6 +276,10 @@ bool PiscsiImage::SetImagePermissions(const CommandContext& context) const
 
 	const bool protect = context.GetCommand().operation() == PROTECT_IMAGE;
 
+	if (protect && !IsReservedFile(context, full_filename, "protect")) {
+		return false;
+	}
+
 	try {
 		permissions(path(full_filename), protect ?
 				perms::owner_read | perms::group_read | perms::others_read :
diff --git a/cpp/test/mocks.h b/cpp/test/mocks.h
index 9b315392f3..fcf45cd524 100644
--- a/cpp/test/mocks.h
+++ b/cpp/test/mocks.h
@@ -14,15 +14,10 @@
 #include "test_shared.h"
 #include "hal/bus.h"
 #include "controllers/scsi_controller.h"
-#include "devices/primary_device.h"
-#include "devices/storage_device.h"
-#include "devices/disk.h"
-#include "devices/scsihd.h"
 #include "devices/scsihd_nec.h"
 #include "devices/scsicd.h"
 #include "devices/scsimo.h"
 #include "devices/host_services.h"
-#include "piscsi/command_context.h"
 #include "piscsi/piscsi_executor.h"
 #include <fcntl.h>
 
diff --git a/cpp/test/piscsi_executor_test.cpp b/cpp/test/piscsi_executor_test.cpp
index a4a917afed..d6557be4a8 100644
--- a/cpp/test/piscsi_executor_test.cpp
+++ b/cpp/test/piscsi_executor_test.cpp
@@ -15,7 +15,6 @@
 #include "generated/piscsi_interface.pb.h"
 #include "piscsi/command_context.h"
 #include "piscsi/piscsi_response.h"
-#include "piscsi/piscsi_image.h"
 #include "piscsi/piscsi_executor.h"
 #include <filesystem>
 
@@ -31,8 +30,7 @@ TEST(PiscsiExecutorTest, ProcessDeviceCmd)
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
 	MockAbstractController controller(bus, ID);
-	PiscsiImage piscsi_image;
-	auto executor = make_shared<MockPiscsiExecutor>(piscsi_image, *bus, controller_manager);
+	auto executor = make_shared<MockPiscsiExecutor>(*bus, controller_manager);
 	PbDeviceDefinition definition;
 	PbCommand command;
 	CommandContext context(command, "", "");
@@ -115,8 +113,7 @@ TEST(PiscsiExecutorTest, ProcessCmd)
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
 	MockAbstractController controller(bus, 0);
-	PiscsiImage piscsi_image;
-	auto executor = make_shared<MockPiscsiExecutor>(piscsi_image, *bus, controller_manager);
+	auto executor = make_shared<MockPiscsiExecutor>(*bus, controller_manager);
 
 	PbCommand command_detach_all;
 	command_detach_all.set_operation(DETACH_ALL);
@@ -167,35 +164,6 @@ TEST(PiscsiExecutorTest, ProcessCmd)
 	device2->set_unit(1);
 	CommandContext context_attach2(command_attach2, "", "");
 	EXPECT_FALSE(executor->ProcessCmd(context_attach2)) << "LUN 0 is missing";
-
-	// The operations below must fail because of missing parameters.
-	// The respective functionality is tested in piscsi_image_test.cpp.
-
-	PbCommand command;
-
-	command.set_operation(CREATE_IMAGE);
-	CommandContext context_create_image(command, "", "");
-	EXPECT_FALSE(executor->ProcessCmd(context_create_image));
-
-	command.set_operation(DELETE_IMAGE);
-	CommandContext context_delete_image(command, "", "");
-	EXPECT_FALSE(executor->ProcessCmd(context_delete_image));
-
-	command.set_operation(RENAME_IMAGE);
-	CommandContext context_rename_image(command, "", "");
-	EXPECT_FALSE(executor->ProcessCmd(context_rename_image));
-
-	command.set_operation(COPY_IMAGE);
-	CommandContext context_copy_image(command, "", "");
-	EXPECT_FALSE(executor->ProcessCmd(context_copy_image));
-
-	command.set_operation(PROTECT_IMAGE);
-	CommandContext context_protect_image(command, "", "");
-	EXPECT_FALSE(executor->ProcessCmd(context_protect_image));
-
-	command.set_operation(UNPROTECT_IMAGE);
-	CommandContext context_unprotect_image(command, "", "");
-	EXPECT_FALSE(executor->ProcessCmd(context_unprotect_image));
 }
 
 TEST(PiscsiExecutorTest, Attach)
@@ -206,8 +174,7 @@ TEST(PiscsiExecutorTest, Attach)
 	DeviceFactory device_factory;
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 	PbDeviceDefinition definition;
 	PbCommand command;
 	CommandContext context(command, "", "");
@@ -290,8 +257,7 @@ TEST(PiscsiExecutorTest, Insert)
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
 	auto [controller, device] = CreateDevice(SCHD);
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 	PbDeviceDefinition definition;
 	PbCommand command;
 	CommandContext context(command, "", "");
@@ -348,8 +314,7 @@ TEST(PiscsiExecutorTest, Detach)
 	DeviceFactory device_factory;
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 	PbCommand command;
 	CommandContext context(command, "", "");
 
@@ -375,8 +340,7 @@ TEST(PiscsiExecutorTest, DetachAll)
 	DeviceFactory device_factory;
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 
 	auto device = device_factory.CreateDevice(SCHS, 0, "");
 	EXPECT_TRUE(controller_manager.AttachToController(*bus, ID, device));
@@ -388,31 +352,12 @@ TEST(PiscsiExecutorTest, DetachAll)
 	EXPECT_TRUE(controller_manager.GetAllDevices().empty());
 }
 
-TEST(PiscsiExecutorTest, ShutDown)
-{
-	auto bus = make_shared<MockBus>();
-	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
-
-	PbCommand command;
-	command.set_operation(SHUT_DOWN);
-	CommandContext context(command, "", "");
-	EXPECT_FALSE(executor.ShutDown(context, ""));
-	EXPECT_FALSE(executor.ShutDown(context, "xyz"));
-
-	EXPECT_FALSE(executor.ShutDown(context, "system")) << "Only available for the root user";
-	EXPECT_FALSE(executor.ShutDown(context, "reboot")) << "Only available for the root user";
-	EXPECT_TRUE(executor.ShutDown(context, "rascsi"));
-}
-
 TEST(PiscsiExecutorTest, SetReservedIds)
 {
 	DeviceFactory device_factory;
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 
 	string error = executor.SetReservedIds("xyz");
 	EXPECT_FALSE(error.empty());
@@ -451,8 +396,7 @@ TEST(PiscsiExecutorTest, ValidateImageFile)
 	DeviceFactory device_factory;
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 	PbCommand command;
 	CommandContext context(command, "", "");
 
@@ -466,8 +410,7 @@ TEST(PiscsiExecutorTest, PrintCommand)
 {
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 	PbDeviceDefinition definition;
 
 	PbCommand command;
@@ -493,8 +436,7 @@ TEST(PiscsiExecutorTest, EnsureLun0)
 	DeviceFactory device_factory;
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 	PbCommand command;
 
 	auto device1 = command.add_devices();
@@ -521,8 +463,7 @@ TEST(PiscsiExecutorTest, VerifyExistingIdAndLun)
 	DeviceFactory device_factory;
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 	PbCommand command;
 	CommandContext context(command, "", "");
 
@@ -537,8 +478,7 @@ TEST(PiscsiExecutorTest, CreateDevice)
 {
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 	PbCommand command;
 	CommandContext context(command, "", "");
 
@@ -555,8 +495,7 @@ TEST(PiscsiExecutorTest, SetSectorSize)
 {
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 	PbCommand command;
 	CommandContext context(command, "", "");
 
@@ -575,8 +514,7 @@ TEST(PiscsiExecutorTest, ValidateOperationAgainstDevice)
 {
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 	PbCommand command;
 	CommandContext context(command, "", "");
 
@@ -629,8 +567,7 @@ TEST(PiscsiExecutorTest, ValidateIdAndLun)
 {
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 	PbCommand command;
 	CommandContext context(command, "", "");
 
@@ -646,8 +583,7 @@ TEST(PiscsiExecutorTest, SetProductData)
 {
 	auto bus = make_shared<MockBus>();
 	ControllerManager controller_manager;
-	PiscsiImage piscsi_image;
-	PiscsiExecutor executor(piscsi_image, *bus, controller_manager);
+	PiscsiExecutor executor(*bus, controller_manager);
 	PbCommand command;
 	CommandContext context(command, "", "");
 	PbDeviceDefinition definition;
diff --git a/cpp/test/piscsi_response_test.cpp b/cpp/test/piscsi_response_test.cpp
index 5fe6ac1a37..510c263739 100644
--- a/cpp/test/piscsi_response_test.cpp
+++ b/cpp/test/piscsi_response_test.cpp
@@ -17,6 +17,7 @@
 #include <sys/stat.h>
 
 using namespace piscsi_interface;
+using namespace spdlog;
 using namespace protobuf_util;
 
 TEST(PiscsiResponseTest, Operation_Count)
diff --git a/cpp/test/test_shared.cpp b/cpp/test/test_shared.cpp
index 91e8c4f649..3ab8ad29cd 100644
--- a/cpp/test/test_shared.cpp
+++ b/cpp/test/test_shared.cpp
@@ -11,7 +11,6 @@
 #include "mocks.h"
 #include "shared/piscsi_exceptions.h"
 #include "shared/piscsi_version.h"
-#include <filesystem>
 #include <fstream>
 #include <iostream>
 #include <sstream>