diff --git a/check_synology.py b/check_synology.py
index 9c4e2e7..e068ff9 100755
--- a/check_synology.py
+++ b/check_synology.py
@@ -3,10 +3,12 @@ import sys
 import traceback
 from enum import Enum
 
+# from pycparser.c_ast import Union as PycUnion
 from pysnmp.hlapi import *
 
 from checker import nagios
 from checker.result import quit_check
+from checker.units import human_readable_size
 
 """
 https://github.com/SnejPro/check_synology/blob/main/check_synology.py
@@ -40,6 +42,23 @@ class SnmpDisk(Enum):
     disk = '1.3.6.1.4.1.6574.2.1.1'
 
 
+class SnmpStorage(Enum):
+    desc = '1.3.6.1.2.1.25.2.3.1.3'
+    allocated_pre = '1.3.6.1.2.1.25.2.3.1.4.'
+    size_pre = '1.3.6.1.2.1.25.2.3.1.5.'
+    used_pre = '1.3.6.1.2.1.25.2.3.1.6.'
+
+
+def format_bytes(size: int, unit):
+    power = 10 ** 3
+    n = 0
+    power_labels = {0: '', 1: 'K', 2: 'M', 3: 'G', 4: 'T'}
+    while size > power:
+        size /= power
+        n += 1
+    return size, power_labels[n] + unit, str(round(size, 2)) + ' ' + power_labels[n] + unit
+
+
 def check_failed(value: str):
     if value == '1':
         exit_code = nagios.STATE_OK
@@ -115,6 +134,18 @@ def walk_snmp(host, community, oid):
     return result
 
 
+def parse_walk(data: dict):
+    disk_indices = set(key.split('.')[-1] for key in data.keys())
+    parsed = []
+    for index in disk_indices:
+        disk_info = []
+        for key, value in data.items():
+            if key.endswith(index):
+                disk_info.append(value)
+        parsed.append(disk_info)
+    return parsed
+
+
 def main(args):
     if args.choice == 'mem':
         mem_unused = query_snmp(args.host, args.community, SnmpMem.unused.value)
@@ -213,22 +244,14 @@ def main(args):
         })
     elif args.choice == 'disks':
         data = walk_snmp(args.host, args.community, SnmpDisk.disk.value)
-        disk_indices = set(key.split('.')[-1] for key in data.keys())
-        disk_data = []
-        for index in disk_indices:
-            disk_info = []
-            for key, value in data.items():
-                if key.endswith(index):
-                    disk_info.append(value)
-            disk_data.append(disk_info)
-
+        disk_data = parse_walk(data)
         result_str = ''
         perfdata_dict = {}
         exit_code = nagios.STATE_OK
         for disk, data in enumerate(disk_data):
             output, value, d_exit_code = check_disk_status(data[4])
             exit_code = d_exit_code
-            result_str = result_str + f'Disk {disk + 1}: {output}'
+            result_str = result_str + f'Disk {disk + 1}: {output}. '
             perfdata_dict[f'disk_{disk + 1}_status'] = {
                 'value': value,
                 'unit': '',
@@ -238,15 +261,59 @@ def main(args):
                 'value': data[5],
                 'unit': 'C'
             }
-        quit_check(result_str, exit_code, perfdata_dict)
+        quit_check(result_str.strip(' '), exit_code, perfdata_dict)
     elif args.choice == 'storage':
-        raise NotImplementedError
+        store_list = walk_snmp(args.host, args.community, SnmpStorage.desc.value)
+        result_str = ''
+        perfdata_dict = {}
+        exit_codes = []
+        for k, name in store_list.items():
+            if not name.startswith('/volume'):
+                continue
+            store_id = k.split('.')[-1]
+            allocated = int(query_snmp(args.host, args.community, SnmpStorage.allocated_pre.value + store_id))
+            size = int(query_snmp(args.host, args.community, SnmpStorage.size_pre.value + store_id)) * allocated
+            used = int(query_snmp(args.host, args.community, SnmpStorage.used_pre.value + store_id)) * allocated
+            used_percent = round((used / size) * 100, 1)
+            result_str = result_str + f'{name}: {human_readable_size(used, decimal_places=0)}/{human_readable_size(size, decimal_places=0)} ({used_percent}%). '
+            perf_name = name.replace('/', '')
+            perfdata_dict[f'{perf_name}_size'] = {
+                'value': size,
+                'unit': 'B',
+                'min': 0
+            }
+            perfdata_dict[f'{perf_name}_used'] = {
+                'value': used,
+                'unit': 'B',
+                'min': 0
+            }
+            perfdata_dict[f'{perf_name}_used_percent'] = {
+                'value': used_percent,
+                'unit': '%',
+                'min': 0
+            }
+            if used_percent >= float(args.crit_store):
+                exit_codes.append(nagios.STATE_CRIT)
+            elif used_percent >= float(args.warn_store):
+                exit_codes.append(nagios.STATE_WARN)
+            else:
+                exit_codes.append(nagios.STATE_OK)
+        quit_check(result_str.strip(' '), max(exit_codes), perfdata_dict)
     elif args.choice == 'network':
         raise NotImplementedError
     else:
         raise Exception
 
 
+def validate_int_float_arg(arg, name):
+    try:
+        arg = float(arg)
+    except:
+        raise Exception(f'{name} must be an int or float')
+    if not isinstance(arg, (int, float)):
+        raise Exception(f'{name} must be an int or float')
+
+
 if __name__ == '__main__':
     parser = argparse.ArgumentParser()
     parser.add_argument('-H', '--host', required=True, help='The host to connect to.')
@@ -255,9 +322,14 @@ if __name__ == '__main__':
 
     parser.add_argument('--warn-mem', type=int, default=75, help='Memory usage percent to warn at. Default: 75%')
     parser.add_argument('--crit-mem', type=int, default=90, help='Memory usage percent to crit at. Default: 90%')
+    parser.add_argument('--warn-store', default=75, help='Storage usage percent to warn at. Default: 65%')
+    parser.add_argument('--crit-store', default=90, help='Storage usage percent to crit at. Default: 70%')
 
     args = parser.parse_args()
 
+    validate_int_float_arg(args.warn_store, '--warn-store')
+    validate_int_float_arg(args.crit_store, '--crit-store')
+
     try:
         main(args)
     except Exception as e: