diff --git a/tuned/plugins/plugin_disk.py b/tuned/plugins/plugin_disk.py
index ed28669..6d700c7 100644
--- a/tuned/plugins/plugin_disk.py
+++ b/tuned/plugins/plugin_disk.py
@@ -1,3 +1,4 @@
+import errno
 import tuned.consts as consts
 import hotplug
 from decorators import *
@@ -100,25 +101,28 @@ class DiskPlugin(hotplug.Plugin):
 			self._monitors_repository.delete(instance._load_monitor)
 			instance._load_monitor = None
 
-	def _update_spindown_errcnt(self, rc):
-		if rc == 0:
-			self._spindown_errcnt = 0
+	def _update_errcnt(self, rc, spindown):
+		if spindown:
+			s = "spindown"
+			cnt = self._spindown_errcnt
 		else:
-			if self._spindown_errcnt > consts.ERROR_THRESHOLD:
-				return
-			self._spindown_errcnt += 1
-			if self._spindown_errcnt == consts.ERROR_THRESHOLD:
-				log.info("disabling set_spindown command, too many consecutive errors")
-
-	def _update_apm_errcnt(self, rc):
+			s = "apm"
+			cnt = self._apm_errcnt
+		if cnt >= consts.ERROR_THRESHOLD:
+			return
 		if rc == 0:
-			self._apm_errcnt = 0
+			cnt = 0
+		elif rc == errno.ENOENT:
+			cnt = consts.ERROR_THRESHOLD + 1
+			log.info("hdparm command not found, ignoring future set_%s commands" % s)
 		else:
-			if self._apm_errcnt > consts.ERROR_THRESHOLD:
-				return
-			self._apm_errcnt += 1
-			if self._apm_errcnt == consts.ERROR_THRESHOLD:
-				log.info("disabling set_apm command, too many consecutive errors")
+			cnt += 1
+			if cnt == consts.ERROR_THRESHOLD:
+				log.info("disabling set_%s command: too many consecutive errors" % s)
+		if spindown:
+			self._spindown_errcnt = cnt
+		else:
+			self._apm_errcnt = cnt
 
 	def _instance_update_dynamic(self, instance, device):
 		load = instance._load_monitor.get_device_load(device)
@@ -154,11 +158,11 @@ class DiskPlugin(hotplug.Plugin):
 			if self._spindown_errcnt < consts.ERROR_THRESHOLD:
 				log.debug("changing spindown to %d" % new_spindown_level)
 				(rc, out) = self._cmd.execute(["hdparm", "-S%d" % new_spindown_level, "/dev/%s" % device])
-				self._update_spindown_errcnt(rc)
+				self._update_errcnt(rc, True)
 			if self._apm_errcnt < consts.ERROR_THRESHOLD:
 				log.debug("changing APM_level to %d" % new_power_level)
 				(rc, out) = self._cmd.execute(["hdparm", "-B%d" % new_power_level, "/dev/%s" % device])
-				self._update_apm_errcnt(rc)
+				self._update_errcnt(rc, False)
 
 		log.debug("%s load: read %0.2f, write %0.2f" % (device, stats["read"], stats["write"]))
 		log.debug("%s idle: read %d, write %d, level %d" % (device, idle["read"], idle["write"], idle["level"]))
@@ -250,7 +254,7 @@ class DiskPlugin(hotplug.Plugin):
 		if self._apm_errcnt < consts.ERROR_THRESHOLD:
 			if not sim:
 				(rc, out) = self._cmd.execute(["hdparm", "-B", str(value), "/dev/" + device])
-				self._update_apm_errcnt(rc)
+				self._update_errcnt(rc, False)
 			return str(value)
 		else:
 			return None
@@ -271,7 +275,7 @@ class DiskPlugin(hotplug.Plugin):
 		if self._spindown_errcnt < consts.ERROR_THRESHOLD:
 			if not sim:
 				(rc, out) = self._cmd.execute(["hdparm", "-S", str(value), "/dev/" + device])
-				self._update_spindown_errcnt(rc)
+				self._update_errcnt(rc, True)
 			return str(value)
 		else:
 			return None
diff --git a/tuned/utils/commands.py b/tuned/utils/commands.py
index 4c89ea4..90311a2 100644
--- a/tuned/utils/commands.py
+++ b/tuned/utils/commands.py
@@ -1,3 +1,4 @@
+import errno
 import tuned.logs
 import copy
 import os
@@ -78,7 +79,7 @@ class commands:
 
 	# "no_errors" can be list of return codes not treated as errors
 	def execute(self, args, no_errors = []):
-		retcode = None
+		retcode = 0
 		if self._environment is None:
 			self._environment = os.environ.copy()
 			self._environment["LC_ALL"] = "C"
@@ -95,8 +96,8 @@ class commands:
 				if len(err_out) == 0:
 					err_out = out[:-1]
 				self._error("Executing %s error: %s" % (args[0], err_out))
-		except (OSError,IOError) as e:
-			retcode = -1
+		except (OSError, IOError) as e:
+			retcode = e.errno if e.errno is not None else -1
 			self._error("Executing %s error: %s" % (args[0], e))
 		return retcode, out