diff --git a/src/vmm_mad/remotes/lib/lxd/mapper/mapper.rb b/src/vmm_mad/remotes/lib/lxd/mapper/mapper.rb
index 15ca6745a0..e6fcd68221 100644
--- a/src/vmm_mad/remotes/lib/lxd/mapper/mapper.rb
+++ b/src/vmm_mad/remotes/lib/lxd/mapper/mapper.rb
@@ -446,4 +446,31 @@ class Mapper
         end
     end
 
+    # Returns true if device has mapped partitions
+    def parts_on?(device)
+        partitions = lsblk(device)
+        return true if partitions[0]['type'] == 'part'
+
+        false
+    end
+
+    def show_parts(device)
+        action_parts(device, '-s -av')
+    end
+
+    def hide_parts(device)
+        action_parts(device, '-d')
+    end
+
+    # Runs kpartx vs a device with required flags as arguments
+    def action_parts(device, action)
+        cmd = "#{COMMANDS[:kpartx]} #{action} #{device}"
+        rc, _out, err = Command.execute(cmd, false)
+
+        return true if rc.zero?
+
+        OpenNebula.log_error("#{__method__}: #{err}")
+        false
+    end
+
 end
diff --git a/src/vmm_mad/remotes/lib/lxd/mapper/qcow2.rb b/src/vmm_mad/remotes/lib/lxd/mapper/qcow2.rb
index a1d706c7f8..51e4dc7aba 100644
--- a/src/vmm_mad/remotes/lib/lxd/mapper/qcow2.rb
+++ b/src/vmm_mad/remotes/lib/lxd/mapper/qcow2.rb
@@ -24,7 +24,7 @@ class Qcow2Mapper < Mapper
 
     # Max number of block devices. This should be set to the parameter used
     # to load the nbd kernel module (default in kernel is 16)
-    NBDS_MAX = 256
+    NBDS_MAX = 256 # TODO: Read system config file
 
     def do_map(one_vm, disk, _directory)
         device = nbd_device
@@ -35,7 +35,7 @@ class Qcow2Mapper < Mapper
         File.chmod(0o664, dsrc) if File.symlink?(one_vm.sysds_path)
 
         map = "#{COMMANDS[:nbd]} -c #{device} #{dsrc}"
-        rc, _out, err = Command.execute(map, false)
+        rc, _out, err = Command.execute(map, true)
 
         unless rc.zero?
             OpenNebula.log_error("#{__method__}: #{err}")
@@ -43,7 +43,7 @@ class Qcow2Mapper < Mapper
         end
 
         # TODO: improve wait condition
-        sleep 5 # wait for parts to come out
+        sleep 1 # wait for parts to come out
 
         show_parts(device) unless parts_on?(device)
 
@@ -69,36 +69,8 @@ class Qcow2Mapper < Mapper
 
     private
 
-    # Returns true if device has mapped partitions
-    def parts_on?(device)
-        partitions = lsblk(device)
-        return true if partitions[0]['type'] == 'part'
-
-        false
-    end
-
-    def show_parts(device)
-        action_parts(device, '-s -av')
-    end
-
-    def hide_parts(device)
-        action_parts(device, '-d')
-    end
-
-    # Runs kpartx vs a device with required flags as arguments
-    def action_parts(device, action)
-        cmd = "#{COMMANDS[:kpartx]} #{action} #{device}"
-        rc, _out, err = Command.execute(cmd, false)
-
-        return true if rc.zero?
-
-        OpenNebula.log_error("#{__method__}: #{err}")
-        false
-    end
-
     def nbd_device
         sys_parts = lsblk('')
-        device_id = -1
         nbds      = []
 
         sys_parts.each do |p|
diff --git a/src/vmm_mad/remotes/lib/lxd/mapper/rbd.rb b/src/vmm_mad/remotes/lib/lxd/mapper/rbd.rb
index d99ec413b7..081008d0a7 100644
--- a/src/vmm_mad/remotes/lib/lxd/mapper/rbd.rb
+++ b/src/vmm_mad/remotes/lib/lxd/mapper/rbd.rb
@@ -19,6 +19,7 @@
 $LOAD_PATH.unshift File.dirname(__FILE__)
 
 require 'mapper'
+require 'tmpdir'
 
 # Ceph RBD mapper
 class RBDMapper < Mapper
@@ -32,15 +33,20 @@ class RBDMapper < Mapper
 
         cmd = "#{COMMANDS[:rbd]} #{@ceph_user} map #{dsrc}"
 
-        rc, out, err = Command.execute(cmd, false)
+        rc, out, err = Command.execute(cmd, true)
+
+        unless rc.zero?
+
+            OpenNebula.log_error("#{__method__}: #{err}")
+            return
+        end
 
         # TODO: improve wait condition
-        sleep 5 # wait for partition table
+        sleep 1 # wait for partition table
 
-        return out.chomp if rc.zero?
-
-        OpenNebula.log_error("#{__method__}: #{err}")
-        nil
+        # TODO: deprecate workaround for ubuntu 16.04 not
+        # updating partition tables
+        try_mount(out.chomp)
     end
 
     def do_unmap(device, _one_vm, _disk, _directory)
@@ -54,4 +60,16 @@ class RBDMapper < Mapper
         nil
     end
 
+    private
+
+    # This function tries to mount mapped devices to force update of partition
+    # tables
+    def try_mount(device)
+        dev = device
+        dev += "p1" if parts_on?(device)
+
+        cmd = "#{COMMANDS[:mount]} --fake #{dev} /mnt"
+
+        device
+    end
 end