Huge amount of image storage in volumes

gistfile1.py

import json
import pyexiv2
import os
import shutil

from models import StorageVolume

STORAGE_CONFIG = {
    'bits_levels': [ 2, 1 ],
    'volumes': [
        {
            'id': 1,
            'name': 'data01', 
            'path': '/srv/images_volumes/data01',
            'range': [ 0, 30 ],
        },
        {
            'id': 2,
            'name': 'data02', 
            'path': '/srv/images_volumes/data02',
            'range': [ 31, 100 ],
        },
        {
            'id': 3,
            'name': 'data03', 
            'path': '/srv/images_volumes/data03',
            'range': [ 100, 150 ],
        },
    ]
}

def get_folder( id ):
    for volume in STORAGE_CONFIG['volumes']:
        if id >= volume['range'][0] and id <= volume['range'][1]:
            return volume
    
    print "CRITICAL: NO VOLUME FOUND"
    return None

def get_id_folders(id, levels_bits):

    previous_bits = 0
    directories = []
    for level_bits in reversed(levels_bits):
        mask = 2**level_bits - 1
        id = id >> previous_bits
        #directory = format(id & mask, 'x').zfill(levels_bits/)
        directory = id & mask
        directories.insert(0, directory)
        previous_bits = level_bits

    return directories

def get_image_store_dst ( id ):
    volume = get_folder(id)
    if volume == None:
        return None

    directories = get_id_folders( id, STORAGE_CONFIG['bits_levels'])

    relative_path = ('/'.join(str(x) for x in directories))
    full_path = volume['path']+'/' + relative_path 

    return { 
    'relative_path': relative_path, 
    'full_path': full_path, 
    'image_path': full_path+'/'+str(id)+'.jpg',
    'volume_id': volume['id']
    }

def save_image_metadata (image_path, metadata):
    
    metadata = pyexiv2.ImageMetadata(image_path)
    metadata.read()
    metadata['Exif.Photo.UserComment'] = json.dumps(metadata)
    metadata.write()

def store_image( id, src_path, move = False, metadata = None):

#    if metadata != None:
#        save_image_metadata(src_path, metadata)

    store_data = get_image_store_dst( id )

    if not os.path.exists(store_data['full_path']):
        os.makedirs(store_data['full_path'])

    dst_filename = store_data['full_path'] + "/" + str(id) + '.jpg'

    if move:
        shutil.move(src_path, dst_filename)
    else:
        shutil.copyfile(src_path, dst_filename)

    return store_data