diff --git a/zun/container/docker/driver.py b/zun/container/docker/driver.py
index e469e7627..4474dffd7 100644
--- a/zun/container/docker/driver.py
+++ b/zun/container/docker/driver.py
@@ -1121,10 +1121,12 @@ class DockerDriver(driver.ContainerDriver):
             (output, err) = utils.execute('df', '-B', '1G',
                                           CONF.docker.docker_data_root,
                                           run_as_root=True)
-        except exception.CommandError:
+        except exception.CommandError as e:
             LOG.info('There was a problem while executing df -B 1G %s',
                      CONF.docker.docker_data_root)
-            raise exception.CommandError(cmd='df')
+            raise exception.CommandError(cmd='df',
+                                         error=six.text_type(e))
+
         total_disk = int(output.split('\n')[1].split()[1])
         return int(total_disk * (1 - CONF.compute.reserve_disk_for_image))
 
diff --git a/zun/container/os_capability/host_capability.py b/zun/container/os_capability/host_capability.py
index 5bba703a9..96d47dfeb 100644
--- a/zun/container/os_capability/host_capability.py
+++ b/zun/container/os_capability/host_capability.py
@@ -15,6 +15,7 @@
 
 from oslo_concurrency import processutils
 from oslo_serialization import jsonutils
+import six
 
 from zun.common import exception
 from zun.common import utils
@@ -85,8 +86,9 @@ class Host(object):
                 columns = line.split()
                 address = columns[0]
                 addresses.append(address)
-        except processutils.ProcessExecutionError:
-            raise exception.CommandError(cmd='lspci')
+        except processutils.ProcessExecutionError as e:
+            raise exception.CommandError(cmd='lspci',
+                                         error=six.text_type(e))
 
         pci_info = []
         for addr in addresses: