diff --git a/CMakeModules/CalamaresAddPlugin.cmake b/CMakeModules/CalamaresAddPlugin.cmake
index e02102829..d2f878381 100644
--- a/CMakeModules/CalamaresAddPlugin.cmake
+++ b/CMakeModules/CalamaresAddPlugin.cmake
@@ -38,6 +38,7 @@
 #   RESOURCES resource-file
 #   [NO_INSTALL]
 #   [SHARED_LIB]
+#   [EMERGENCY]
 # )
 
 include( CMakeParseArguments )
@@ -47,7 +48,7 @@ include( CMakeColors )
 function( calamares_add_plugin )
     # parse arguments ( name needs to be saved before passing ARGN into the macro )
     set( NAME ${ARGV0} )
-    set( options NO_INSTALL SHARED_LIB )
+    set( options NO_INSTALL SHARED_LIB EMERGENCY )
     set( oneValueArgs NAME TYPE EXPORT_MACRO RESOURCES )
     set( multiValueArgs SOURCES UI LINK_LIBRARIES LINK_PRIVATE_LIBRARIES COMPILE_DEFINITIONS )
     cmake_parse_arguments( PLUGIN "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN} )
@@ -71,7 +72,7 @@ function( calamares_add_plugin )
 #        message( "   ${Green}NO_INSTALL:${ColorReset} ${PLUGIN_NO_INSTALL}" )
         message( "   ${Green}PLUGIN_DESTINATION:${ColorReset} ${PLUGIN_DESTINATION}" )
         if( PLUGIN_CONFIG_FILES )
-            if ( INSTALL_CONFIG )
+            if ( INSTALL_CONFIG AND NOT PLUGIN_NO_INSTALL )
                 message( "   ${Green}CONFIGURATION_FILES:${ColorReset} ${PLUGIN_CONFIG_FILES} => ${PLUGIN_DATA_DESTINATION}" )
             else()
                 message( "   ${Green}CONFIGURATION_FILES:${ColorReset} ${PLUGIN_CONFIG_FILES} => [Skipping installation]" )
@@ -92,7 +93,7 @@ function( calamares_add_plugin )
         set( target_type "SHARED" )
     endif()
 
-    list( APPEND calamares_add_library_args
+    set( calamares_add_library_args
         "${target}"
         "EXPORT_MACRO" "${PLUGIN_EXPORT_MACRO}"
         "TARGET_TYPE" "${target_type}"
@@ -115,9 +116,14 @@ function( calamares_add_plugin )
         list( APPEND calamares_add_library_args "COMPILE_DEFINITIONS" ${PLUGIN_COMPILE_DEFINITIONS} )
     endif()
 
-    list( APPEND calamares_add_library_args "NO_VERSION" )
+    if ( PLUGIN_NO_INSTALL )
+        list( APPEND calamares_add_library_args "NO_INSTALL" )
+    endif()
 
-    list( APPEND calamares_add_library_args "INSTALL_BINDIR" "${PLUGIN_DESTINATION}" )
+    list( APPEND calamares_add_library_args
+        "NO_VERSION"
+        "INSTALL_BINDIR" "${PLUGIN_DESTINATION}"
+    )
 
     if( PLUGIN_RESOURCES )
         list( APPEND calamares_add_library_args "RESOURCES" "${PLUGIN_RESOURCES}" )
@@ -132,16 +138,21 @@ function( calamares_add_plugin )
         set( _type ${PLUGIN_TYPE} )
         file( WRITE  ${_file} "# AUTO-GENERATED metadata file\n# Syntax is YAML 1.2\n---\n" )
         file( APPEND ${_file} "type: \"${_type}\"\nname: \"${PLUGIN_NAME}\"\ninterface: \"qtplugin\"\nload: \"lib${target}.so\"\n" )
+        if ( PLUGIN_EMERGENCY )
+            file( APPEND ${_file} "emergency: true\n" )
+        endif()
     endif()
 
-    install( FILES ${CMAKE_CURRENT_BINARY_DIR}/${PLUGIN_DESC_FILE}
-             DESTINATION ${PLUGIN_DESTINATION} )
+    if ( NOT PLUGIN_NO_INSTALL )
+        install( FILES ${CMAKE_CURRENT_BINARY_DIR}/${PLUGIN_DESC_FILE}
+                DESTINATION ${PLUGIN_DESTINATION} )
 
-    if ( INSTALL_CONFIG )
-        foreach( PLUGIN_CONFIG_FILE ${PLUGIN_CONFIG_FILES} )
-            configure_file( ${PLUGIN_CONFIG_FILE} ${PLUGIN_CONFIG_FILE} COPYONLY )
-            install( FILES ${CMAKE_CURRENT_BINARY_DIR}/${PLUGIN_CONFIG_FILE}
-                     DESTINATION ${PLUGIN_DATA_DESTINATION} )
-        endforeach()
+        if ( INSTALL_CONFIG )
+            foreach( PLUGIN_CONFIG_FILE ${PLUGIN_CONFIG_FILES} )
+                configure_file( ${PLUGIN_CONFIG_FILE} ${PLUGIN_CONFIG_FILE} COPYONLY )
+                install( FILES ${CMAKE_CURRENT_BINARY_DIR}/${PLUGIN_CONFIG_FILE}
+                        DESTINATION ${PLUGIN_DATA_DESTINATION} )
+            endforeach()
+        endif()
     endif()
 endfunction()
diff --git a/src/libcalamares/Job.h b/src/libcalamares/Job.h
index 6063633b8..040ead6ad 100644
--- a/src/libcalamares/Job.h
+++ b/src/libcalamares/Job.h
@@ -66,8 +66,15 @@ public:
     virtual QString prettyDescription() const;
     virtual QString prettyStatusMessage() const;
     virtual JobResult exec() = 0;
+
+    bool isEmergency() const { return m_emergency; }
+    void setEmergency( bool e ) { m_emergency = e; }
+
 signals:
     void progress( qreal percent );
+
+private:
+    bool m_emergency = false;
 };
 
 } // namespace Calamares
diff --git a/src/libcalamares/JobQueue.cpp b/src/libcalamares/JobQueue.cpp
index 257fb51a7..46d58d429 100644
--- a/src/libcalamares/JobQueue.cpp
+++ b/src/libcalamares/JobQueue.cpp
@@ -51,22 +51,36 @@ public:
 
     void run() override
     {
+        bool anyFailed = false;
+        QString message;
+        QString details;
+
         m_jobIndex = 0;
         for( auto job : m_jobs )
         {
+            if ( anyFailed && !job->isEmergency() )
+            {
+                cDebug() << "Skipping non-emergency job" << job->prettyName();
+                continue;
+            }
+
             emitProgress();
-            cDebug() << "Starting job" << job->prettyName();
+            cDebug() << "Starting" << ( anyFailed ? "EMERGENCY JOB" : "job" ) << job->prettyName();
             connect( job.data(), &Job::progress, this, &JobThread::emitProgress );
             JobResult result = job->exec();
-            if ( !result )
+            if ( !anyFailed && !result )
             {
-                emitFailed( result.message(), result.details() );
-                emitFinished();
-                return;
+                anyFailed = true;
+                message = result.message();
+                details = result.details();
             }
-            ++m_jobIndex;
+            if ( !anyFailed )
+                ++m_jobIndex;
         }
-        emitProgress();
+        if ( anyFailed )
+            emitFailed( message, details );
+        else
+            emitProgress();
         emitFinished();
     }
 
diff --git a/src/libcalamaresui/ExecutionViewStep.cpp b/src/libcalamaresui/ExecutionViewStep.cpp
index 109bd1384..b505102a4 100644
--- a/src/libcalamaresui/ExecutionViewStep.cpp
+++ b/src/libcalamaresui/ExecutionViewStep.cpp
@@ -21,6 +21,7 @@
 #include <ExecutionViewStep.h>
 
 #include "Branding.h"
+#include "Job.h"
 #include "JobQueue.h"
 #include "modulesystem/Module.h"
 #include "modulesystem/ModuleManager.h"
@@ -142,7 +143,15 @@ ExecutionViewStep::onActivate()
         Calamares::Module* module = Calamares::ModuleManager::instance()
                                     ->moduleInstance( instanceKey );
         if ( module )
-            queue->enqueue( module->jobs() );
+        {
+            auto jl = module->jobs();
+            if ( module->isEmergency() )
+            {
+                for( auto& j : jl )
+                    j->setEmergency( true );
+            }
+            queue->enqueue( jl );
+        }
     }
 
     queue->start();
diff --git a/src/libcalamaresui/modulesystem/Module.cpp b/src/libcalamaresui/modulesystem/Module.cpp
index 758ee5e47..9b3be877f 100644
--- a/src/libcalamaresui/modulesystem/Module.cpp
+++ b/src/libcalamaresui/modulesystem/Module.cpp
@@ -52,6 +52,8 @@ name:      "foo"      #the module name. must be unique and same as the parent di
 interface: "qtplugin" #can be: qtplugin, python, process, ...
 */
 
+static const char EMERGENCY[] = "emergency";
+
 namespace Calamares
 {
 
@@ -64,7 +66,7 @@ Module::fromDescriptor( const QVariantMap& moduleDescriptor,
                         const QString& configFileName,
                         const QString& moduleDirectory )
 {
-    Module* m = nullptr;
+    std::unique_ptr<Module> m;
 
     QString typeString = moduleDescriptor.value( "type" ).toString();
     QString intfString = moduleDescriptor.value( "interface" ).toString();
@@ -79,12 +81,12 @@ Module::fromDescriptor( const QVariantMap& moduleDescriptor,
     {
         if ( intfString == "qtplugin" )
         {
-            m = new ViewModule();
+            m.reset( new ViewModule() );
         }
         else if ( intfString == "pythonqt" )
         {
 #ifdef WITH_PYTHONQT
-            m = new PythonQtViewModule();
+            m.reset( new PythonQtViewModule() );
 #else
             cError() << "PythonQt view modules are not supported in this version of Calamares.";
 #endif
@@ -96,16 +98,16 @@ Module::fromDescriptor( const QVariantMap& moduleDescriptor,
     {
         if ( intfString == "qtplugin" )
         {
-            m = new CppJobModule();
+            m.reset( new CppJobModule() );
         }
         else if ( intfString == "process" )
         {
-            m = new ProcessJobModule();
+            m.reset( new ProcessJobModule() );
         }
         else if ( intfString == "python" )
         {
 #ifdef WITH_PYTHON
-            m = new PythonJobModule();
+            m.reset( new PythonJobModule() );
 #else
             cError() << "Python modules are not supported in this version of Calamares.";
 #endif
@@ -130,7 +132,6 @@ Module::fromDescriptor( const QVariantMap& moduleDescriptor,
     else
     {
         cError() << "Bad module directory" << moduleDirectory << "for" << instanceId;
-        delete m;
         return nullptr;
     }
 
@@ -144,10 +145,9 @@ Module::fromDescriptor( const QVariantMap& moduleDescriptor,
     catch ( YAML::Exception& e )
     {
         cError() << "YAML parser error " << e.what();
-        delete m;
         return nullptr;
     }
-    return m;
+    return m.release();
 }
 
 
@@ -200,6 +200,9 @@ Module::loadConfigurationFile( const QString& configFileName ) //throws YAML::Ex
             }
 
             m_configurationMap = CalamaresUtils::yamlMapToVariant( doc ).toMap();
+            m_emergency = m_maybe_emergency
+                && m_configurationMap.contains( EMERGENCY )
+                && m_configurationMap[ EMERGENCY ].toBool();
             return;
         }
         else
@@ -276,13 +279,6 @@ Module::interfaceString() const
 }
 
 
-bool
-Module::isLoaded() const
-{
-    return m_loaded;
-}
-
-
 QVariantMap
 Module::configurationMap()
 {
@@ -299,6 +295,11 @@ void
 Module::initFrom( const QVariantMap& moduleDescriptor )
 {
     m_name = moduleDescriptor.value( "name" ).toString();
+
+    if ( moduleDescriptor.contains( EMERGENCY ) )
+    {
+        m_maybe_emergency = moduleDescriptor[ EMERGENCY ].toBool();
+    }
 }
 
 } //ns
diff --git a/src/libcalamaresui/modulesystem/Module.h b/src/libcalamaresui/modulesystem/Module.h
index 896d3b597..4fd0020f8 100644
--- a/src/libcalamaresui/modulesystem/Module.h
+++ b/src/libcalamaresui/modulesystem/Module.h
@@ -147,7 +147,7 @@ public:
      * @brief isLoaded reports on the loaded status of a module.
      * @return true if the module's loading phase has finished, otherwise false.
      */
-    virtual bool isLoaded() const;
+    bool isLoaded() const { return m_loaded; }
 
     /**
      * @brief loadSelf initialized the module.
@@ -155,6 +155,17 @@ public:
      */
     virtual void loadSelf() = 0;
 
+    /**
+     * @brief Is this an emergency module?
+     *
+     * An emergency module is run even if an error occurs
+     * which would terminate Calamares earlier in the same
+     * *exec* block. Emergency modules in later exec blocks
+     * are not run (in the common case where there is only
+     * one exec block, this doesn't really matter).
+     */
+    bool isEmergency() const { return m_emergency; }
+
     /**
      * @brief jobs returns any jobs exposed by this module.
      * @return a list of jobs (can be empty).
@@ -171,11 +182,15 @@ public:
 protected:
     explicit Module();
     virtual void initFrom( const QVariantMap& moduleDescriptor );
-    bool m_loaded;
     QVariantMap m_configurationMap;
 
+    bool m_loaded = false;
+    bool m_emergency = false;  // Based on module and local config
+    bool m_maybe_emergency = false;  // Based on the module.desc
+
 private:
     void loadConfigurationFile( const QString& configFileName ); //throws YAML::Exception
+
     QString m_name;
     QStringList m_requiredModules;
     QString m_directory;
diff --git a/src/modules/README.md b/src/modules/README.md
index a2ec06144..bd6cd4e37 100644
--- a/src/modules/README.md
+++ b/src/modules/README.md
@@ -43,15 +43,21 @@ module's name, type, interface and possibly other properties. The name
 of the module as defined in `module.desc` must be the same as the name
 of the module's directory.
 
-Module descriptors must have the following keys:
+Module descriptors **must** have the following keys:
 - *name* (an identifier; must be the same as the directory name)
 - *type* ("job" or "view")
 - *interface* (see below for the different interfaces; generally we
   refer to the kinds of modules by their interface)
 
+Module descriptors **may** have the following keys:
+- *required* **unimplemented** (a list of modules which are required for this module
+  to operate properly)
+- *emergency* (a boolean value, set to true to mark the module
+  as an emergency module)
+
 ## Module-specific configuration
 
-A Calamares module *may* read a module configuration file,
+A Calamares module **may** read a module configuration file,
 named `<modulename>.conf`. If such a file is present in the
 module's directory, it is shipped as a *default* configuration file.
 The module configuration file, if it exists, is a YAML 1.2 document
@@ -125,3 +131,23 @@ while the module type must be "job" or "jobmodule".
 The key *command* should have a string as value, which is passed to the
 shell -- remember to quote it properly.
 
+## Emergency Modules
+
+Only C++ modules and job modules may be emergency modules. If, during an
+*exec* step in the sequence, a module fails, installation as a whole fails
+and the install is aborted. If there are emergency modules in the **same**
+exec block, those will be executed before the installation is aborted.
+Non-emergency modules are not executed.
+
+If an emergency-module fails while processing emergency-modules for
+another failed module, that failure is ignored and emergency-module
+processing continues.
+
+Use the EMERGENCY keyword in the CMake description of a C++ module
+to generate a suitable `module.desc`.
+
+A module that is marked as an emergency module in its module.desc
+must **also** set the *emergency* key to *true* in its configuration file.
+If it does not, the module is not considered to be an emergency module
+after all (this is so that you can have modules that have several
+instances, only some of which are actually needed for emergencies.
diff --git a/src/modules/preservefiles/CMakeLists.txt b/src/modules/preservefiles/CMakeLists.txt
index 43602024c..1ac979d1b 100644
--- a/src/modules/preservefiles/CMakeLists.txt
+++ b/src/modules/preservefiles/CMakeLists.txt
@@ -8,4 +8,5 @@ calamares_add_plugin( preservefiles
     LINK_PRIVATE_LIBRARIES
         calamares
     SHARED_LIB
+    EMERGENCY
 )
diff --git a/src/modules/preservefiles/module.desc b/src/modules/preservefiles/module.desc
deleted file mode 100644
index 953d8c81b..000000000
--- a/src/modules/preservefiles/module.desc
+++ /dev/null
@@ -1,5 +0,0 @@
----
-type:      "job"
-name:      "preservefiles"
-interface: "qtplugin"
-load:      "libcalamares_job_preservefiles.so"