Index: vws
==================================================================
--- vws
+++ vws
@@ -347,28 +347,39 @@
 def cmd_commit(options):   
     #
     # Commits last snapshot changes into it's backing file
     #
     if options.stopped:
-       #
-       # Stoppend vm - last snapshot is commited into its backing file.
-       # Backing file is made current drive image
-       #
-       os.chdir(options.dir)
-       for drive in get_drives(options.dir):
+        #
+        # Stoppend vm - last snapshot is commited into its backing file.
+        # Backing file is made current drive image
+        #
+        os.chdir(options.dir)
+        found=0
+        for drive in get_drives(options.dir):
             backing=get_backing(drive)
             if backing is None:
                 continue
+            found=1
             os.system('qemu-img commit "%s"'%drive)
             os.unlink(drive)
             os.rename(backing,drive)
+        if not found:
+            print >>sys.stderr,"No snapshots exist for this VM"
+            sys.exit(1)
+        
     else:
-       #
-       #
-       # Check if we are running in the snapshot mode
-       # 
-       send_command(options.sock,"commit")
+        #
+        #
+        # Check if we are running in the snapshot mode
+        # 
+        answer=send_command(options.sock,"info block")
+        if re.search(": /tmp",answer):
+            send_command(options.sock,"commit")
+        else:
+            print >>sys.stderr,"VM is not running in snapshot mode"
+            sys.exit(1)
 
     
 
 
 template="""#!/bin/sh
@@ -512,18 +523,20 @@
     """
     p=cmds.add_parser(name,**kwargs)
     p.add_argument('machine',type=str,help='name of vm to operate on')
     return p
 #
-# arg parsing
+# prepare defaults for config
 #
 
 arch=os.uname()[4]
 if re.match("i[3-9]86",arch):
     arch="i386"
 elif arch.startswith("arm"):
     arch="arm"
+
+
 config=ConfigParser({'SharedVMs':'/var/cache/vws/shared',
     'AutoStartVMs':'/var/cache/vws/autostart'})
 config.add_section('directories')
 config.add_section('create options')
 for option,value in [('net','user'),('size','20G'),('mem','1G'),
@@ -532,12 +545,13 @@
     config.set('create options',option,value)
 config.add_section('tools')
 config.set('tools','viewer','remote-viewer %s')
 config.set('tools','bridge_list','/sbin/brctl show')
 config.set('tools','lsusb','lsusb')
+# Read configration files
 config.read(['/etc/vws.conf',os.environ['HOME']+'/.vwsrc'])
-print config
+# Parse argument
 args=ArgumentParser(description="Manage Virtual Workstations")
 cmds=args.add_subparsers(dest='command',help="sub-command help")
 p=cmds.add_parser("list",help="List existing VWs",description="List existing VWs")
 p.add_argument("--state",action='store_const',const=True,default=False,
                 dest='state',help='Show state of the machine')