diff --git a/shell/src/interpreter.py b/shell/src/interpreter.py

index a10ca4a8..64641a02 100644

--- a/shell/src/interpreter.py

+++ b/shell/src/interpreter.py

@@ -13,6 +13,8 @@ import re

 import time

 import dateutil.parser

 import pycurl

+import traceback

+

 try:

     from urllib.parse import unquote

 except ImportError:

@@ -159,20 +161,7 @@ class DMLiteInterpreter(object):

             return None

     def prettySize(self, size):

-        isize = int(size) # argument can be string

-        if isize < 1024**1:

-            prettySize = "%iB" % isize

-        elif isize < 1024**2:

-            prettySize = '%.2fkB' % (float(isize) / 1024**1)

-        elif isize < 1024**3:

-            prettySize = '%.2fMB' % (float(isize) / 1024**2)

-        elif isize < 1024**4:

-            prettySize = '%.2fGB' % (float(isize) / 1024**3)

-        elif isize < 1024**5:

-            prettySize = '%.2fTB' % (float(isize) / 1024**4)

-        else:

-            prettySize = '%.2fPB' % (float(isize) / 1024**5)

-        return prettySize

+        return prettySize(size)

     def prettyInputSize(self, prettysize):

         if 'PB' in prettysize:

@@ -1715,31 +1704,52 @@ The latter is the default.

         except Exception as e:

             return self.error(e.__str__() + '\nParameter(s): ' + ', '.join(given))

+def prettySize(size):

+    isize = int(size) # argument can be string

+    if isize < 1024**1:

+        prettySize = "%iB" % isize

+    elif isize < 1024**2:

+        prettySize = '%.2fkB' % (float(isize) / 1024**1)

+    elif isize < 1024**3:

+        prettySize = '%.2fMB' % (float(isize) / 1024**2)

+    elif isize < 1024**4:

+        prettySize = '%.2fGB' % (float(isize) / 1024**3)

+    elif isize < 1024**5:

+        prettySize = '%.2fTB' % (float(isize) / 1024**4)

+    else:

+        prettySize = '%.2fPB' % (float(isize) / 1024**5)

+    return prettySize

+

 def pprint_dictionary(dpool, indent=4):

-    ret = StringIO.StringIO()

+    ret = ''

     for key, value in dpool.items():

-        ret.write(" " * indent)

-        ret.write(key)

-        ret.write(": ")

+        ret += (" " * indent)

+        ret += key

+        ret += ": "

         if type(value) is dict:

-            ret.write(pprint_dictionary(value, indent + 4))

+            ret += pprint_dictionary(value, indent + 4)

         elif type(value) is list and len(value) > 0 and type(value[0]) is dict:

             for item in value:

-                ret.write("\n")

-                ret.write(pprint_dictionary(item, indent + 4))

-            ret.write("\n")

+                ret += "\n"

+                ret += pprint_dictionary(item, indent + 4) 

+            ret += "\n"

         #workaround to print the status and activitystatus as String

         elif str(key) in ["status", "poolstatus"]:

-            ret.write(fsstatusbycode[int(value)])

-            ret.write("\n")

+            ret += fsstatusbycode[int(value)]

+            ret += "\n"

+        elif "space" in key or "size" in key:

+            ret += str(value)

+            ret += " ("

+            ret += prettySize(value)

+            ret += ")\n" 

         elif str(key) in ["activitystatus"]:

-            ret.write(activitystatusbycode[int(value)])

-            ret.write("\n")

+            ret += activitystatusbycode[int(value)]

+            ret += "\n"

         else:

-            ret.write(str(value))

-            ret.write("\n")

-    return ret.getvalue()

+            ret += str(value)

+            ret += "\n"

+    return ret

 class PoolInfoCommand(ShellCommand):

@@ -1773,7 +1783,7 @@ class PoolInfoCommand(ShellCommand):

                 self.ok("%s (%s)\n%s" % (pool.name, pool.type, pprint_dictionary(dpool)))

             return self.ok()

         except Exception as e:

-            return self.error(e.__str__() + '\nParameter(s): ' + ', '.join(given))

+            return self.error(e.__str__() + '\n' + traceback.format_exc() + '\nParameter(s): ' + ', '.join(given))

 class PoolModifyCommand(ShellCommand):