diff --git a/netbox_agent/raid/hp.py b/netbox_agent/raid/hp.py
index 7089918..82d3c06 100644
--- a/netbox_agent/raid/hp.py
+++ b/netbox_agent/raid/hp.py
@@ -7,10 +7,26 @@ import re
 
 REGEXP_CONTROLLER_HP = re.compile(r'Smart Array ([a-zA-Z0-9- ]+) in Slot ([0-9]+)')
 
+class HPRaidControllerError(Exception):
+    pass
 
-def ssacli(command):
-    output = subprocess.getoutput('ssacli {}'.format(command) )
-    lines = output.split('\n')
+
+def ssacli(sub_command):
+    command = ["ssacli"]
+    command.extend(sub_command.split())
+    p = subprocess.Popen(
+        command,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT
+    )
+    p.wait()
+    stdout = p.stdout.read().decode("utf-8")
+    if p.returncode != 0:
+        mesg = "Failed to execute command '{}':\n{}".format(
+            " ".join(command), stdout
+        )
+        raise HPRaidControllerError(mesg)
+    lines = stdout.split('\n')
     lines = list(filter(None, lines))
     return lines
 
@@ -92,8 +108,10 @@ class HPRaidController(RaidController):
         self.controller_name = controller_name
         self.data = data
         self.pdrives = self._get_physical_disks()
-        self.ldrives = self._get_logical_drives()
-        self._get_virtual_drives_map()
+        arrays = [d['Array'] for d in self.pdrives.values() if d.get('Array')]
+        if arrays:
+            self.ldrives = self._get_logical_drives()
+            self._get_virtual_drives_map()
 
     def get_product_name(self):
         return self.controller_name
@@ -135,6 +153,7 @@ class HPRaidController(RaidController):
                 'Type': 'SSD' if attrs.get('Interface Type') == 'Solid State SATA'
                 else 'HDD',
                 '_src': self.__class__.__name__,
+                'custom_fields':  {'pd_identifier': name}
             }
         return ret
 
@@ -164,8 +183,7 @@ class HPRaidController(RaidController):
                     " Ignoring.".format(name)
                 )
                 continue
-            attrs['custom_fields'] = ld
-            attrs['custom_fields']['pd_identifier'] = name
+            attrs['custom_fields'].update(ld)
 
     def get_physical_disks(self):
         return list(self.pdrives.values())
diff --git a/netbox_agent/raid/omreport.py b/netbox_agent/raid/omreport.py
index 6b4f780..811761b 100644
--- a/netbox_agent/raid/omreport.py
+++ b/netbox_agent/raid/omreport.py
@@ -6,15 +6,32 @@ import logging
 import re
 
 
+class OmreportControllerError(Exception):
+    pass
+
+
 def omreport(sub_command):
-    command = 'omreport {}'.format(sub_command)
-    output = subprocess.getoutput(command)
+    command = ["omreport"]
+    command.extend(sub_command.split())
+    p = subprocess.Popen(
+        command,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT
+    )
+    p.wait()
+    stdout = p.stdout.read().decode("utf-8")
+    if p.returncode != 0:
+        mesg = "Failed to execute command '{}':\n{}".format(
+            " ".join(command), stdout
+        )
+        raise OmreportControllerError(mesg)
+
     res = {}
     section_re = re.compile('^[A-Z]')
     current_section = None
     current_obj = None
 
-    for line in output.split('\n'):
+    for line in stdout.split('\n'):
         if ': ' in line:
             attr, value = line.split(': ', 1)
             attr = attr.strip()
diff --git a/netbox_agent/raid/storcli.py b/netbox_agent/raid/storcli.py
index ee15fcf..c80380c 100644
--- a/netbox_agent/raid/storcli.py
+++ b/netbox_agent/raid/storcli.py
@@ -8,10 +8,27 @@ import re
 import os
 
 
+class StorcliControllerError(Exception):
+    pass
+
+
 def storecli(sub_command):
-    command = 'storcli {} J'.format(sub_command)
-    output = subprocess.getoutput(command)
-    data = json.loads(output)
+    command = ["storcli"]
+    command.extend(sub_command.split())
+    command.append("J")
+    p = subprocess.Popen(
+        command,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT
+    )
+    p.wait()
+    stdout = p.stdout.read().decode("utf-8")
+    if p.returncode != 0:
+        mesg = "Failed to execute command '{}':\n{}".format(
+            " ".join(command), stdout
+        )
+        raise StorcliControllerError(mesg)
+    data = json.loads(stdout)
     controllers = dict([
         (
             c['Command Status']['Controller'],
@@ -22,7 +39,7 @@ def storecli(sub_command):
     if not controllers:
         logging.error(
             "Failed to execute command '{}'. "
-            "Ignoring data.".format(command)
+            "Ignoring data.".format(" ".join(command))
         )
         return {}
     return controllers