diff --git a/grive/src/main.cc b/grive/src/main.cc
index e522a1e..0ce91b0 100644
--- a/grive/src/main.cc
+++ b/grive/src/main.cc
@@ -26,8 +26,9 @@
 
 #include "bfd/Backtrace.hh"
 #include "util/Exception.hh"
-#include "util/Log.hh"
-#include "util/DefaultLog.hh"
+#include "util/log/Log.hh"
+#include "util/log/CompositeLog.hh"
+#include "util/log/DefaultLog.hh"
 
 #include <boost/exception/all.hpp>
 
@@ -45,13 +46,13 @@ int main( int argc, char **argv )
 
 	Config config ;
 	
-	DefaultLog nofile_log ;
-	LogBase::Inst( &nofile_log ) ;
+	std::auto_ptr<log::CompositeLog> comp_log(new log::CompositeLog) ;
+	LogBase* console_log = comp_log->Add( std::auto_ptr<LogBase>( new log::DefaultLog ) ) ;
 	
 	Json options ;
 	
 	int c ;
-	while ((c = getopt(argc, argv, "al:vVf")) != -1)
+	while ((c = getopt(argc, argv, "al:vVfd")) != -1)
 	{
 		switch ( c )
 		{
@@ -81,8 +82,14 @@ int main( int argc, char **argv )
 			
 			case 'l' :
 			{
-				static DefaultLog log( optarg ) ;
-				LogBase::Inst( &log ) ;
+				std::auto_ptr<LogBase> file_log(new log::DefaultLog(optarg)) ;
+				file_log->Enable( log::debug ) ;
+				file_log->Enable( log::verbose ) ;
+				file_log->Enable( log::info ) ;
+				file_log->Enable( log::warning ) ;
+				file_log->Enable( log::error ) ;
+				file_log->Enable( log::critical ) ;
+				comp_log->Add( file_log ) ;
 				break ;
 			}
 			
@@ -95,7 +102,14 @@ int main( int argc, char **argv )
 			
 			case 'V' :
 			{
-				LogBase::Inst()->Enable( log::verbose ) ;
+				console_log->Enable( log::verbose ) ;
+				break ;
+			}
+			
+			case 'd' :
+			{
+				console_log->Enable( log::verbose ) ;
+				console_log->Enable( log::debug ) ;
 				break ;
 			}
 			
@@ -106,7 +120,7 @@ int main( int argc, char **argv )
 			}
 		}
 	}
-		
+	LogBase::Inst( std::auto_ptr<LogBase>(comp_log.release()) ) ;
 	
 	std::string refresh_token ;
 	try
diff --git a/libgrive/CMakeLists.txt b/libgrive/CMakeLists.txt
index ba17ce9..b57cdcc 100644
--- a/libgrive/CMakeLists.txt
+++ b/libgrive/CMakeLists.txt
@@ -58,6 +58,7 @@ file (GLOB LIBGRIVE_SRC
 	src/http/*.cc
 	src/protocol/*.cc
 	src/util/*.cc
+	src/util/log/*.cc
 	src/xml/*.cc
 )
 
diff --git a/libgrive/src/drive/Drive.cc b/libgrive/src/drive/Drive.cc
index 456cc1b..cb74091 100644
--- a/libgrive/src/drive/Drive.cc
+++ b/libgrive/src/drive/Drive.cc
@@ -28,7 +28,7 @@
 #include "protocol/Json.hh"
 #include "protocol/OAuth2.hh"
 #include "util/Destroy.hh"
-#include "util/Log.hh"
+#include "util/log/Log.hh"
 #include "xml/Node.hh"
 #include "xml/NodeSet.hh"
 
diff --git a/libgrive/src/drive/Entry.cc b/libgrive/src/drive/Entry.cc
index ba77408..f67a3b4 100644
--- a/libgrive/src/drive/Entry.cc
+++ b/libgrive/src/drive/Entry.cc
@@ -21,7 +21,7 @@
 #include "CommonUri.hh"
 
 #include "util/Crypt.hh"
-#include "util/Log.hh"
+#include "util/log/Log.hh"
 #include "util/OS.hh"
 #include "xml/Node.hh"
 #include "xml/NodeSet.hh"
diff --git a/libgrive/src/drive/Resource.cc b/libgrive/src/drive/Resource.cc
index ffd692c..61d03b4 100644
--- a/libgrive/src/drive/Resource.cc
+++ b/libgrive/src/drive/Resource.cc
@@ -28,7 +28,7 @@
 #include "protocol/Json.hh"
 #include "util/CArray.hh"
 #include "util/Crypt.hh"
-#include "util/Log.hh"
+#include "util/log/Log.hh"
 #include "util/OS.hh"
 #include "util/StdioFile.hh"
 #include "xml/Node.hh"
diff --git a/libgrive/src/drive/ResourceTree.cc b/libgrive/src/drive/ResourceTree.cc
index 0523ce3..8dd9d59 100644
--- a/libgrive/src/drive/ResourceTree.cc
+++ b/libgrive/src/drive/ResourceTree.cc
@@ -22,7 +22,7 @@
 
 #include "protocol/Json.hh"
 #include "util/Destroy.hh"
-#include "util/Log.hh"
+#include "util/log/Log.hh"
 
 #include <algorithm>
 #include <cassert>
diff --git a/libgrive/src/drive/State.cc b/libgrive/src/drive/State.cc
index bdf5bac..db628c4 100644
--- a/libgrive/src/drive/State.cc
+++ b/libgrive/src/drive/State.cc
@@ -24,7 +24,7 @@
 
 #include "http/Agent.hh"
 #include "util/Crypt.hh"
-#include "util/Log.hh"
+#include "util/log/Log.hh"
 #include "protocol/Json.hh"
 
 #include <boost/bind.hpp>
diff --git a/libgrive/src/http/Agent.cc b/libgrive/src/http/Agent.cc
index 0866826..c689ae7 100644
--- a/libgrive/src/http/Agent.cc
+++ b/libgrive/src/http/Agent.cc
@@ -23,7 +23,7 @@
 #include "Error.hh"
 #include "Receivable.hh"
 
-#include "util/Log.hh"
+#include "util/log/Log.hh"
 
 #include <boost/throw_exception.hpp>
 
diff --git a/libgrive/src/http/XmlResponse.cc b/libgrive/src/http/XmlResponse.cc
index 586a916..49395f1 100644
--- a/libgrive/src/http/XmlResponse.cc
+++ b/libgrive/src/http/XmlResponse.cc
@@ -19,7 +19,6 @@
 
 #include "XmlResponse.hh"
 
-#include "util/Log.hh"
 #include "xml/Node.hh"
 #include "xml/TreeBuilder.hh"
 
diff --git a/libgrive/src/protocol/OAuth2.cc b/libgrive/src/protocol/OAuth2.cc
index 17afd7f..6b7cade 100644
--- a/libgrive/src/protocol/OAuth2.cc
+++ b/libgrive/src/protocol/OAuth2.cc
@@ -23,7 +23,7 @@
 #include "Json.hh"
 
 #include "http/Agent.hh"
-#include "util/Log.hh"
+#include "util/log/Log.hh"
 
 // for debugging
 #include <iostream>
diff --git a/libgrive/src/util/log/CommonLog.cc b/libgrive/src/util/log/CommonLog.cc
new file mode 100644
index 0000000..d9cab05
--- /dev/null
+++ b/libgrive/src/util/log/CommonLog.cc
@@ -0,0 +1,50 @@
+/*
+	grive: an GPL program to sync a local directory with Google Drive
+	Copyright (C) 2012  Wan Wai Ho
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation version 2
+	of the License.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+#include "CommonLog.hh"
+
+namespace gr { namespace log {
+
+CommonLog::CommonLog()
+{
+	m_enabled[log::debug]		= false ;
+	m_enabled[log::verbose]		= false ;
+	m_enabled[log::info]		= true ;
+	m_enabled[log::warning]		= true ;
+	m_enabled[log::error]		= true ;
+	m_enabled[log::critical]	= true ;
+}
+
+bool CommonLog::Enable( log::Serverity s, bool enable )
+{
+	assert( s >= debug && s < serverity_count ) ;
+	
+	bool prev = m_enabled[s] ;
+	m_enabled[s] = enable ;
+	
+	return prev ;
+}
+
+bool CommonLog::IsEnabled( log::Serverity s ) const
+{
+	assert( s >= debug && s < serverity_count ) ;
+	return m_enabled[s] ;
+}
+
+}} // end of namespace
diff --git a/libgrive/src/util/log/CommonLog.hh b/libgrive/src/util/log/CommonLog.hh
new file mode 100644
index 0000000..a8e910e
--- /dev/null
+++ b/libgrive/src/util/log/CommonLog.hh
@@ -0,0 +1,40 @@
+/*
+	grive: an GPL program to sync a local directory with Google Drive
+	Copyright (C) 2012  Wan Wai Ho
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation version 2
+	of the License.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+#pragma once
+
+#include "Log.hh"
+
+#include <bitset>
+
+namespace gr { namespace log {
+
+class CommonLog : public LogBase
+{
+public :
+	CommonLog() ;
+	
+	bool Enable( log::Serverity s, bool enable = true ) ;
+	bool IsEnabled( log::Serverity s ) const ;
+	
+private :
+	std::bitset<serverity_count>	m_enabled ;
+} ;
+
+} } // end of namespace
diff --git a/libgrive/src/util/log/CompositeLog.cc b/libgrive/src/util/log/CompositeLog.cc
new file mode 100644
index 0000000..6c9140a
--- /dev/null
+++ b/libgrive/src/util/log/CompositeLog.cc
@@ -0,0 +1,57 @@
+/*
+	grive: an GPL program to sync a local directory with Google Drive
+	Copyright (C) 2012  Wan Wai Ho
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation version 2
+	of the License.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+#include "CompositeLog.hh"
+
+#include <algorithm>
+#include "util/Destroy.hh"
+
+namespace gr { namespace log {
+
+CompositeLog::CompositeLog()
+{
+	Enable(log::debug,		true) ;
+	Enable(log::verbose,	true) ;
+	Enable(log::info,		true) ;
+	Enable(log::warning,	true) ;
+	Enable(log::error,		true) ;
+	Enable(log::critical,	true) ;
+}
+
+CompositeLog::~CompositeLog()
+{
+	std::for_each( m_logs.begin(), m_logs.end(), Destroy() ) ;
+}
+	
+LogBase* CompositeLog::Add( std::auto_ptr<LogBase> log )
+{
+	m_logs.push_back( log.get() ) ;
+	return log.release() ;
+}
+
+void CompositeLog::Log( const log::Fmt& msg, log::Serverity s )
+{
+	for ( std::vector<LogBase*>::iterator i = m_logs.begin(); i != m_logs.end(); ++i )
+	{
+		if ( IsEnabled(s) && (*i)->IsEnabled(s) )
+			(*i)->Log( msg, s ) ;
+	}
+}
+
+} } // end of namespace
diff --git a/libgrive/src/util/log/CompositeLog.hh b/libgrive/src/util/log/CompositeLog.hh
new file mode 100644
index 0000000..6efe3be
--- /dev/null
+++ b/libgrive/src/util/log/CompositeLog.hh
@@ -0,0 +1,43 @@
+/*
+	grive: an GPL program to sync a local directory with Google Drive
+	Copyright (C) 2012  Wan Wai Ho
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation version 2
+	of the License.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+#pragma once
+
+#include "CommonLog.hh"
+
+#include <memory>
+#include <vector>
+
+namespace gr { namespace log {
+
+class CompositeLog : public CommonLog
+{
+public :
+	CompositeLog() ;
+	~CompositeLog() ;
+	
+	LogBase* Add( std::auto_ptr<LogBase> log ) ;
+
+	void Log( const log::Fmt& msg, log::Serverity s ) ;
+
+private :
+	std::vector<LogBase*>			m_logs ;
+} ;
+
+}} // end of namespace
diff --git a/libgrive/src/util/DefaultLog.cc b/libgrive/src/util/log/DefaultLog.cc
similarity index 63%
rename from libgrive/src/util/DefaultLog.cc
rename to libgrive/src/util/log/DefaultLog.cc
index f279a31..6f4c64d 100644
--- a/libgrive/src/util/DefaultLog.cc
+++ b/libgrive/src/util/log/DefaultLog.cc
@@ -22,35 +22,24 @@
 #include <cassert>
 #include <iostream>
 
-namespace gr {
+namespace gr { namespace log {
 
 DefaultLog::DefaultLog() :
 	m_log( std::cerr )
 {
-	m_enabled[log::debug]		= false ;
-	m_enabled[log::verbose]		= false ;
-	m_enabled[log::info]		= true ;
-	m_enabled[log::warning]		= true ;
-	m_enabled[log::error]		= true ;
-	m_enabled[log::critical]	= true ;
+// 	Enable(log::debug,		true) ;
+// 	Enable(log::verbose,	true) ;
 }
 
 DefaultLog::DefaultLog( const std::string& filename ) :
 	m_file( filename.c_str() ),
 	m_log( m_file )
 {
-	m_enabled[log::debug]		= true ;
-	m_enabled[log::verbose]		= true ;
-	m_enabled[log::info]		= true ;
-	m_enabled[log::warning]		= true ;
-	m_enabled[log::error]		= true ;
-	m_enabled[log::critical]	= true ;
 }
 
 void DefaultLog::Log( const log::Fmt& msg, log::Serverity s )
 {
-	assert( s >= log::debug && s <= log::critical ) ;
-	if ( m_enabled[s] )
+	if ( IsEnabled(s) )
 	{
 		switch ( s )
 		{
@@ -66,12 +55,4 @@ void DefaultLog::Log( const log::Fmt& msg, log::Serverity s )
 	}
 }
 
-bool DefaultLog::Enable( log::Serverity s, bool enable )
-{
-	assert( s >= log::debug && s <= log::critical ) ;
-	bool prev = m_enabled[s] ;
-	m_enabled[s] = enable ;
-	return prev ;
-}
-
-} // end of namespace
+} } // end of namespace
diff --git a/libgrive/src/util/DefaultLog.hh b/libgrive/src/util/log/DefaultLog.hh
similarity index 84%
rename from libgrive/src/util/DefaultLog.hh
rename to libgrive/src/util/log/DefaultLog.hh
index 64625e6..60e92e1 100644
--- a/libgrive/src/util/DefaultLog.hh
+++ b/libgrive/src/util/log/DefaultLog.hh
@@ -19,28 +19,24 @@
 
 #pragma once
 
-#include "Log.hh"
+#include "CommonLog.hh"
 
-#include <bitset>
 #include <fstream>
 #include <string>
 
-namespace gr {
+namespace gr { namespace log {
 
-class DefaultLog : public LogBase
+class DefaultLog : public CommonLog
 {
 public :
 	DefaultLog() ;
 	explicit DefaultLog( const std::string& filename ) ;
 
 	void Log( const log::Fmt& msg, log::Serverity s ) ;
-	bool Enable( log::Serverity s, bool enable ) ;
 	
 private :
 	std::ofstream	m_file ;
 	std::ostream&	m_log ;
-
-	std::bitset<5>	m_enabled ;
 } ;
 
-} // end of namespace
+} } // end of namespace
diff --git a/libgrive/src/util/Log.cc b/libgrive/src/util/log/Log.cc
similarity index 83%
rename from libgrive/src/util/Log.cc
rename to libgrive/src/util/log/Log.cc
index cf89290..b93e1b7 100644
--- a/libgrive/src/util/Log.cc
+++ b/libgrive/src/util/log/Log.cc
@@ -30,23 +30,25 @@ public :
 	{
 	}
 	
-	bool Enable( log::Serverity s, bool enable )
+	bool Enable( log::Serverity, bool enable )
 	{
 		return enable ;
 	}
-
+	bool IsEnabled( log::Serverity ) const
+	{
+		return true ;
+	}
 } ;
 
-LogBase* LogBase::Inst( LogBase *log )
+LogBase* LogBase::Inst( std::auto_ptr<LogBase> log )
 {
-	static MockLog mlog ;
-	static LogBase *inst = &mlog ;
+	static std::auto_ptr<LogBase> inst( new MockLog ) ;
 	
-	if ( log != 0 )
+	if ( log.get() != 0 )
 		inst = log ;
 		
-	assert( inst != 0 ) ;
-	return inst ;
+	assert( inst.get() != 0 ) ;
+	return inst.get() ;
 }
 
 LogBase::LogBase()
diff --git a/libgrive/src/util/Log.hh b/libgrive/src/util/log/Log.hh
similarity index 92%
rename from libgrive/src/util/Log.hh
rename to libgrive/src/util/log/Log.hh
index 043d7b0..8bdd6bb 100644
--- a/libgrive/src/util/Log.hh
+++ b/libgrive/src/util/log/Log.hh
@@ -20,6 +20,7 @@
 #pragma once
 
 #include <boost/format.hpp>
+#include <memory>
 
 namespace gr {
 
@@ -45,7 +46,11 @@ namespace log
 		error,
 		
 		/// grive cannot proceed
-		critical
+		critical,
+		
+		
+		/// must be put at the end, equal to number of serverities
+		serverity_count
 	} ;
 	
 	typedef boost::format Fmt ;
@@ -58,12 +63,13 @@ class LogBase
 public :
 	virtual void Log( const log::Fmt& msg, log::Serverity s = log::info ) = 0 ;
 	virtual bool Enable( log::Serverity s, bool enable = true ) = 0 ;
+	virtual bool IsEnabled( log::Serverity s ) const = 0 ;
 	
-	static LogBase* Inst( LogBase *log = 0 ) ;
+	static LogBase* Inst( std::auto_ptr<LogBase> log = std::auto_ptr<LogBase>() ) ;
+	~LogBase() ;
 
 protected :
 	LogBase() ;
-	~LogBase() ;
 } ;
 
 class DisableLog
diff --git a/libgrive/test/UnitTest.cc b/libgrive/test/UnitTest.cc
index e793f5f..f599edf 100644
--- a/libgrive/test/UnitTest.cc
+++ b/libgrive/test/UnitTest.cc
@@ -19,7 +19,7 @@
 
 #include <cppunit/ui/text/TestRunner.h>
 
-#include "util/DefaultLog.hh"
+#include "util/log/DefaultLog.hh"
 
 #include "drive/EntryTest.hh"
 #include "drive/ResourceTest.hh"
@@ -34,10 +34,8 @@ int main( int argc, char **argv )
 {
 	using namespace grut ;
 	
-	gr::DefaultLog nofile_log ;
-	nofile_log.Enable( gr::log::debug, true ) ;
-	gr::LogBase::Inst( &nofile_log ) ;
-
+	gr::LogBase::Inst( std::auto_ptr<gr::LogBase>(new gr::log::DefaultLog) ) ;
+	
 	CppUnit::TextUi::TestRunner runner;
 	runner.addTest( EntryTest::suite( ) ) ;
 	runner.addTest( StateTest::suite( ) ) ;
diff --git a/libgrive/test/drive/StateTest.cc b/libgrive/test/drive/StateTest.cc
index 4982855..71ed8be 100644
--- a/libgrive/test/drive/StateTest.cc
+++ b/libgrive/test/drive/StateTest.cc
@@ -23,7 +23,7 @@
 
 #include "drive/State.hh"
 #include "protocol/Json.hh"
-#include "util/Log.hh"
+#include "util/log/Log.hh"
 
 #include <iostream>