diff --git a/plugins/guests/linux/cap/mount_smb_shared_folder.rb b/plugins/guests/linux/cap/mount_smb_shared_folder.rb
index bbec27148..bce106c6b 100644
--- a/plugins/guests/linux/cap/mount_smb_shared_folder.rb
+++ b/plugins/guests/linux/cap/mount_smb_shared_folder.rb
@@ -1,29 +1,23 @@
 require "shellwords"
+require_relative "../../../synced_folders/unix_mount_helpers"
 
 module VagrantPlugins
   module GuestLinux
     module Cap
       class MountSMBSharedFolder
+
+        extend SyncedFolder::UnixMountHelpers
+
         def self.mount_smb_shared_folder(machine, name, guestpath, options)
           expanded_guest_path = machine.guest.capability(
             :shell_expand_guest_path, guestpath)
 
-          mount_commands = []
           mount_device   = "//#{options[:smb_host]}/#{name}"
 
-          if options[:owner].is_a? Integer
-            mount_uid = options[:owner]
-          else
-            mount_uid = "`id -u #{options[:owner]}`"
-          end
-
-          if options[:group].is_a? Integer
-            mount_gid = options[:group]
-            mount_gid_old = options[:group]
-          else
-            mount_gid = "`getent group #{options[:group]} | cut -d: -f3`"
-            mount_gid_old = "`id -g #{options[:group]}`"
-          end
+          mount_options = options.fetch(:mount_options, [])
+          detected_ids = detect_owner_group_ids(machine, guest_path, mount_options, options)
+          mount_uid = detected_ids[:uid]
+          mount_gid = detected_ids[:gid]
 
           # If a domain is provided in the username, separate it
           username, domain = (options[:smb_username] || '').split('@', 2)
@@ -33,15 +27,9 @@ module VagrantPlugins
           options[:mount_options] << "sec=ntlm"
           options[:mount_options] << "credentials=/etc/smb_creds_#{name}"
 
-          # First mount command uses getent to get the group
           mount_options = "-o uid=#{mount_uid},gid=#{mount_gid}"
-          mount_options += ",#{options[:mount_options].join(",")}" if options[:mount_options]
-          mount_commands << "mount -t cifs #{mount_options} #{mount_device} #{expanded_guest_path}"
-
-          # Second mount command uses the old style `id -g`
-          mount_options = "-o uid=#{mount_uid},gid=#{mount_gid_old}"
-          mount_options += ",#{options[:mount_options].join(",")}" if options[:mount_options]
-          mount_commands << "mount -t cifs #{mount_options} #{mount_device} #{expanded_guest_path}"
+          mount_options += ",#{Array(options[:mount_options]).join(",")}" if options[:mount_options]
+          mount_command = "mount -t cifs #{mount_options} #{mount_device} #{expanded_guest_path}"
 
           # Create the guest path if it doesn't exist
           machine.communicate.sudo("mkdir -p #{expanded_guest_path}")
@@ -58,46 +46,25 @@ SCRIPT
 
           # Attempt to mount the folder. We retry here a few times because
           # it can fail early on.
-          attempts = 0
-          while true
-            success = true
 
+          retryable(on: Vagrant::Errors::LinuxMountFailed, tries: 10, sleep: 2) do
+            no_such_device = false
             stderr = ""
-            mount_commands.each do |command|
-              no_such_device = false
-              stderr = ""
-              status = machine.communicate.sudo(command, error_check: false) do |type, data|
-                if type == :stderr
-                  no_such_device = true if data =~ /No such device/i
-                  stderr += data.to_s
-                end
+            status = machine.communicate.sudo(mount_command, error_check: false) do |type, data|
+              if type == :stderr
+                no_such_device = true if data =~ /No such device/i
+                stderr += data.to_s
               end
-
-              success = status == 0 && !no_such_device
-              break if success
             end
-
-            break if success
-
-            attempts += 1
-            if attempts > 10
-              command = mount_commands.join("\n")
-              command.gsub!(smb_password, "PASSWORDHIDDEN")
-
+            if status != 0 || no_such_device
+              clean_command = mount_command.gsub(smb_password, "PASSWORDHIDDEN")
               raise Vagrant::Errors::LinuxMountFailed,
-                command: command,
+                command: clean_command,
                 output: stderr
             end
-
-            sleep 2
           end
 
-          # Emit an upstart event if we can
-          machine.communicate.sudo <<-SCRIPT
-if command -v /sbin/init && /sbin/init 2>/dev/null --version | grep upstart; then
-  /sbin/initctl emit --no-wait vagrant-mounted MOUNTPOINT='#{expanded_guest_path}'
-fi
-SCRIPT
+          emit_upstart_notification(machine, expanded_guest_path)
         end
       end
     end
diff --git a/plugins/guests/linux/cap/mount_virtualbox_shared_folder.rb b/plugins/guests/linux/cap/mount_virtualbox_shared_folder.rb
index 4f285cff8..5744565e1 100644
--- a/plugins/guests/linux/cap/mount_virtualbox_shared_folder.rb
+++ b/plugins/guests/linux/cap/mount_virtualbox_shared_folder.rb
@@ -1,67 +1,23 @@
-require "shellwords"
-
-require "vagrant/util/retryable"
+require_relative "../../../synced_folders/unix_mount_helpers"
 
 module VagrantPlugins
   module GuestLinux
     module Cap
       class MountVirtualBoxSharedFolder
-        @@logger = Log4r::Logger.new("vagrant::guest::linux::mount_virtualbox_shared_folder")
-
-        extend Vagrant::Util::Retryable
+        extend SyncedFolder::UnixMountHelpers
 
         def self.mount_virtualbox_shared_folder(machine, name, guestpath, options)
           guest_path = Shellwords.escape(guestpath)
 
           @@logger.debug("Mounting #{name} (#{options[:hostpath]} to #{guestpath})")
 
-          if options[:owner].to_i.to_s == options[:owner].to_s
-            mount_uid = options[:owner]
-            @@logger.debug("Owner user ID (provided): #{mount_uid}")
-          else
-            output = {stdout: '', stderr: ''}
-            uid_command = "id -u #{options[:owner]}"
-            machine.communicate.execute(uid_command,
-              error_class: Vagrant::Errors::VirtualBoxMountFailed,
-              error_key: :virtualbox_mount_failed,
-              command: uid_command,
-              output: output[:stderr]
-            ) { |type, data| output[type] << data if output[type] }
-            mount_uid = output[:stdout].chomp
-            @@logger.debug("Owner user ID (lookup): #{options[:owner]} -> #{mount_uid}")
-          end
-
-          if options[:group].to_i.to_s == options[:group].to_s
-            mount_gid = options[:group]
-            @@logger.debug("Owner group ID (provided): #{mount_gid}")
-          else
-            begin
-              output = {stdout: '', stderr: ''}
-              gid_command = "getent group #{options[:group]}"
-              machine.communicate.execute(gid_command,
-                error_class: Vagrant::Errors::VirtualBoxMountFailed,
-                error_key: :virtualbox_mount_failed,
-                command: gid_command,
-                output: output[:stderr]
-              ) { |type, data| output[type] << data if output[type] }
-              mount_gid = output[:stdout].split(':').at(2)
-              @@logger.debug("Owner group ID (lookup): #{options[:group]} -> #{mount_gid}")
-            rescue Vagrant::Errors::VirtualBoxMountFailed
-              if options[:owner] == options[:group]
-                @@logger.debug("Failed to locate group `#{options[:group]}`. Group name matches owner. Fetching effective group ID.")
-                output = {stdout: ''}
-                result = machine.communicate.execute("id -g #{options[:owner]}",
-                  error_check: false
-                ) { |type, data| output[type] << data if output[type] }
-                mount_gid = output[:stdout].chomp if result == 0
-                @@logger.debug("Owner group ID (effective): #{mount_gid}")
-              end
-              raise unless mount_gid
-            end
-          end
-
           mount_options = options.fetch(:mount_options, [])
-          mount_options += ["uid=#{mount_uid}", "gid=#{mount_gid}"]
+          detected_ids = detect_owner_group_ids(machine, guest_path, mount_options, options)
+          mount_uid = detected_ids[:uid]
+          mount_gid = detected_ids[:gid]
+
+          mount_options << "uid=#{mount_uid}"
+          mount_options << "gid=#{mount_gid}"
           mount_options = mount_options.join(',')
           mount_command = "mount -t vboxsf -o #{mount_options} #{name} #{guest_path}"
 
@@ -87,14 +43,10 @@ module VagrantPlugins
             machine.communicate.sudo(chown_command)
           end
 
-          # Emit an upstart event if we can
-          machine.communicate.sudo <<-EOH.gsub(/^ {12}/, "")
-            if command -v /sbin/init && /sbin/init 2>/dev/null --version | grep upstart; then
-              /sbin/initctl emit --no-wait vagrant-mounted MOUNTPOINT=#{guest_path}
-            fi
-          EOH
+          emit_upstart_notification(machine, guest_path)
         end
 
+
         def self.unmount_virtualbox_shared_folder(machine, guestpath, options)
           guest_path = Shellwords.escape(guestpath)
 
diff --git a/plugins/guests/linux/cap/nfs.rb b/plugins/guests/linux/cap/nfs.rb
index 8dadae1f3..9263688e5 100644
--- a/plugins/guests/linux/cap/nfs.rb
+++ b/plugins/guests/linux/cap/nfs.rb
@@ -1,10 +1,10 @@
-require "vagrant/util/retryable"
+require_relative "../../../synced_folders/unix_mount_helpers"
 
 module VagrantPlugins
   module GuestLinux
     module Cap
       class NFS
-        extend Vagrant::Util::Retryable
+        extend SyncedFolder::UnixMountHelpers
 
         def self.nfs_client_installed(machine)
           machine.communicate.test("test -x /sbin/mount.nfs")
@@ -30,18 +30,7 @@ module VagrantPlugins
 
             machine.communicate.sudo("mkdir -p #{guest_path}")
 
-            # Perform the mount operation and emit mount event if applicable
-            command = <<-EOH.gsub(/^ */, '')
-              mount -o #{mount_opts} #{ip}:#{host_path} #{guest_path}
-              result=$?
-              if test $result -eq 0; then
-                if test -x /sbin/initctl && command -v /sbin/init && /sbin/init 2>/dev/null --version | grep upstart; then
-                  /sbin/initctl emit --no-wait vagrant-mounted MOUNTPOINT=#{guest_path}
-                fi
-              else
-                exit $result
-              fi
-            EOH
+            command = "mount -o #{mount_opts} #{ip}:#{host_path} #{guest_path}"
 
             # Run the command, raising a specific error.
             retryable(on: Vagrant::Errors::NFSMountFailed, tries: 3, sleep: 5) do
@@ -49,6 +38,8 @@ module VagrantPlugins
                 error_class: Vagrant::Errors::NFSMountFailed,
               )
             end
+
+            emit_upstart_notification(machine, guest_path)
           end
         end
       end
diff --git a/plugins/guests/tinycore/cap/mount_nfs.rb b/plugins/guests/tinycore/cap/mount_nfs.rb
index 1f39631b2..e6896ad6e 100644
--- a/plugins/guests/tinycore/cap/mount_nfs.rb
+++ b/plugins/guests/tinycore/cap/mount_nfs.rb
@@ -1,10 +1,10 @@
-require "vagrant/util/retryable"
+require_relative "../../../synced_folders/unix_mount_helpers"
 
 module VagrantPlugins
   module GuestTinyCore
     module Cap
       class MountNFS
-        extend Vagrant::Util::Retryable
+        extend SyncedFolder::UnixMountHelpers
 
         def self.mount_nfs_folder(machine, ip, folders)
           folders.each do |name, opts|
@@ -32,12 +32,7 @@ module VagrantPlugins
                                        error_class: Vagrant::Errors::NFSMountFailed)
             end
 
-            # Emit an upstart event if we can
-            machine.communicate.sudo <<-SCRIPT
-if command -v /sbin/init && /sbin/init --version | grep upstart; then
-  /sbin/initctl emit --no-wait vagrant-mounted MOUNTPOINT='#{expanded_guest_path}'
-fi
-SCRIPT
+            emit_upstart_notification(machine, expanded_guest_path)
           end
         end
       end
diff --git a/plugins/synced_folders/unix_mount_helpers.rb b/plugins/synced_folders/unix_mount_helpers.rb
new file mode 100644
index 000000000..97d77975a
--- /dev/null
+++ b/plugins/synced_folders/unix_mount_helpers.rb
@@ -0,0 +1,105 @@
+require "shellwords"
+require "vagrant/util/retryable"
+
+module VagrantPlugins
+  module SyncedFolder
+    module UnixMountHelpers
+
+      def self.extended(klass)
+        if !klass.class_variable_defined?(:@@logger)
+          klass.class_variable_set(:@@logger, Log4r::Logger.new(klass.name.downcase))
+        end
+        klass.extend Vagrant::Util::Retryable
+      end
+
+      def detect_owner_group_ids(machine, guest_path, mount_options, options)
+        mount_uid = find_mount_options_id("uid", mount_options)
+        mount_gid = find_mount_options_id("gid", mount_options)
+
+        if mount_uid.nil?
+          if options[:owner].to_i.to_s == options[:owner].to_s
+            mount_uid = options[:owner]
+            self.class_variable_get(:@@logger).debug("Owner user ID (provided): #{mount_uid}")
+          else
+            output = {stdout: '', stderr: ''}
+            uid_command = "id -u #{options[:owner]}"
+            machine.communicate.execute(uid_command,
+              error_class: Vagrant::Errors::VirtualBoxMountFailed,
+              error_key: :virtualbox_mount_failed,
+              command: uid_command,
+              output: output[:stderr]
+            ) { |type, data| output[type] << data if output[type] }
+            mount_uid = output[:stdout].chomp
+            self.class_variable_get(:@@logger).debug("Owner user ID (lookup): #{options[:owner]} -> #{mount_uid}")
+          end
+        else
+          machine.ui.warn "Detected mount owner ID within mount options. (uid: #{mount_uid} guestpath: #{guest_path})"
+        end
+
+        if mount_gid.nil?
+          if options[:group].to_i.to_s == options[:group].to_s
+            mount_gid = options[:group]
+            self.class_variable_get(:@@logger).debug("Owner group ID (provided): #{mount_gid}")
+          else
+            begin
+              output = {stdout: '', stderr: ''}
+              gid_command = "getent group #{options[:group]}"
+              machine.communicate.execute(gid_command,
+                error_class: Vagrant::Errors::VirtualBoxMountFailed,
+                error_key: :virtualbox_mount_failed,
+                command: gid_command,
+                output: output[:stderr]
+              ) { |type, data| output[type] << data if output[type] }
+              mount_gid = output[:stdout].split(':').at(2)
+              self.class_variable_get(:@@logger).debug("Owner group ID (lookup): #{options[:group]} -> #{mount_gid}")
+            rescue Vagrant::Errors::VirtualBoxMountFailed
+              if options[:owner] == options[:group]
+                self.class_variable_get(:@@logger).debug("Failed to locate group `#{options[:group]}`. Group name matches owner. Fetching effective group ID.")
+                output = {stdout: ''}
+                result = machine.communicate.execute("id -g #{options[:owner]}",
+                  error_check: false
+                ) { |type, data| output[type] << data if output[type] }
+                mount_gid = output[:stdout].chomp if result == 0
+                self.class_variable_get(:@@logger).debug("Owner group ID (effective): #{mount_gid}")
+              end
+              raise unless mount_gid
+            end
+          end
+        else
+          machine.ui.warn "Detected mount group ID within mount options. (gid: #{mount_gid} guestpath: #{guest_path})"
+        end
+        {:gid => mount_gid, :uid => mount_uid}
+      end
+
+      def find_mount_options_id(id_name, mount_options)
+        id_line = mount_options.detect{|line| line.include?("#{id_name}=")}
+        if id_line
+          match = id_line.match(/,?#{Regexp.escape(id_name)}=(?<option_id>\d+),?/)
+          found_id = match["option_id"]
+          updated_id_line = [
+            match.pre_match,
+            match.post_match
+          ].find_all{|string| !string.empty?}.join(',')
+          if updated_id_line.empty?
+            mount_options.delete(id_line)
+          else
+            idx = mount_options.index(id_line)
+            mount_options.delete(idx)
+            mount_options.insert(idx, updated_id_line)
+          end
+        end
+        found_id
+      end
+
+      def emit_upstart_notification(machine, guest_path)
+        # Emit an upstart event if we can
+        machine.communicate.sudo <<-EOH.gsub(/^ {12}/, "")
+            if command -v /sbin/init && /sbin/init 2>/dev/null --version | grep upstart; then
+              /sbin/initctl emit --no-wait vagrant-mounted MOUNTPOINT=#{guest_path}
+            fi
+          EOH
+      end
+
+    end
+  end
+end
diff --git a/test/unit/plugins/guests/linux/cap/mount_nfs_test.rb b/test/unit/plugins/guests/linux/cap/mount_nfs_test.rb
index 7cec549f2..f1f0a7254 100644
--- a/test/unit/plugins/guests/linux/cap/mount_nfs_test.rb
+++ b/test/unit/plugins/guests/linux/cap/mount_nfs_test.rb
@@ -71,7 +71,7 @@ describe "VagrantPlugins::GuestLinux::Cap::MountNFS" do
       }
       cap.mount_nfs_folder(machine, ip, folders)
 
-      expect(comm.received_commands[1]).to include(
+      expect(comm.received_commands[2]).to include(
         "/sbin/initctl emit --no-wait vagrant-mounted MOUNTPOINT=#{guestpath}")
     end
 
diff --git a/test/unit/plugins/guests/linux/cap/mount_virtual_box_shared_folder_test.rb b/test/unit/plugins/guests/linux/cap/mount_virtual_box_shared_folder_test.rb
index d05e844a8..7c673f511 100644
--- a/test/unit/plugins/guests/linux/cap/mount_virtual_box_shared_folder_test.rb
+++ b/test/unit/plugins/guests/linux/cap/mount_virtual_box_shared_folder_test.rb
@@ -149,6 +149,49 @@ describe "VagrantPlugins::GuestLinux::Cap::MountVirtualBoxSharedFolder" do
         cap.mount_virtualbox_shared_folder(machine, mount_name, mount_guest_path, folder_options)
       end
     end
+
+    context "with custom mount options" do
+
+      let(:ui){ double(:ui) }
+      before do
+        allow(ui).to receive(:warn)
+        allow(machine).to receive(:ui).and_return(ui)
+      end
+
+      context "with uid defined" do
+        let(:options_uid){ '1234' }
+
+        it "should only include uid defined within mount options" do
+          expect(comm).not_to receive(:execute).with("id -u #{mount_owner}", anything).and_yield(:stdout, mount_uid)
+          expect(comm).to receive(:execute).with("getent group #{mount_group}", anything).and_yield(:stdout, "vagrant:x:#{mount_gid}:")
+          expect(comm).to receive(:sudo).with("mount -t vboxsf -o uid=#{options_uid},gid=#{mount_gid} #{mount_name} #{mount_guest_path}", anything)
+          cap.mount_virtualbox_shared_folder(machine, mount_name, mount_guest_path, folder_options.merge(mount_options: ["uid=#{options_uid}"]))
+        end
+      end
+
+      context "with gid defined" do
+        let(:options_gid){ '1234' }
+
+        it "should only include gid defined within mount options" do
+          expect(comm).to receive(:execute).with("id -u #{mount_owner}", anything).and_yield(:stdout, mount_uid)
+          expect(comm).not_to receive(:execute).with("getent group #{mount_group}", anything).and_yield(:stdout, "vagrant:x:#{mount_gid}:")
+          expect(comm).to receive(:sudo).with("mount -t vboxsf -o uid=#{mount_uid},gid=#{options_gid} #{mount_name} #{mount_guest_path}", anything)
+          cap.mount_virtualbox_shared_folder(machine, mount_name, mount_guest_path, folder_options.merge(mount_options: ["gid=#{options_gid}"]))
+        end
+      end
+
+      context "with uid and gid defined" do
+        let(:options_gid){ '1234' }
+        let(:options_uid){ '1234' }
+
+        it "should only include uid and gid defined within mount options" do
+          expect(comm).not_to receive(:execute).with("id -u #{mount_owner}", anything).and_yield(:stdout, mount_uid)
+          expect(comm).not_to receive(:execute).with("getent group #{mount_group}", anything).and_yield(:stdout, "vagrant:x:#{options_gid}:")
+          expect(comm).to receive(:sudo).with("mount -t vboxsf -o uid=#{options_uid},gid=#{options_gid} #{mount_name} #{mount_guest_path}", anything)
+          cap.mount_virtualbox_shared_folder(machine, mount_name, mount_guest_path, folder_options.merge(mount_options: ["gid=#{options_gid}", "uid=#{options_uid}"]))
+        end
+      end
+    end
   end
 
   describe ".unmount_virtualbox_shared_folder" do
diff --git a/website/source/docs/synced-folders/basic_usage.html.md b/website/source/docs/synced-folders/basic_usage.html.md
index 08fa08732..022107a52 100644
--- a/website/source/docs/synced-folders/basic_usage.html.md
+++ b/website/source/docs/synced-folders/basic_usage.html.md
@@ -100,6 +100,19 @@ config.vm.synced_folder "src/", "/srv/website",
   owner: "root", group: "root"
 ```
 
+_NOTE: Owner and group IDs defined within `mount_options` will have precedence
+over the `owner` and `group` options._
+
+For example, given the following configuration:
+
+```ruby
+config.vm.synced_folder ".", "/vagrant", owner: "vagrant",
+  group: "vagrant", mount_options: ["uid=1234", "gid=1234"]
+```
+
+the mounted synced folder will be owned by the user with ID `1234` and the
+group with ID `1234`. The `owner` and `group` options will be ignored.
+
 ## Symbolic Links
 
 Support for symbolic links across synced folder implementations and