merge trunk

15 files changed, 212 insertions, 256 deletions

diff --git a/nova/virt/fake.py b/nova/virt/fake.py
index 77bc926c2..55c6dcef9 100644
--- a/nova/virt/fake.py
+++ b/nova/virt/fake.py
@@ -130,6 +130,18 @@ class FakeConnection(object):
         """
         pass
 
+    def pause(self, instance, callback):
+        """
+        Pause the specified instance.
+        """
+        pass
+
+    def unpause(self, instance, callback):
+        """
+        Unpause the specified instance.
+        """
+        pass
+
     def destroy(self, instance):
         """
         Destroy (shutdown and delete) the specified instance.
@@ -243,5 +255,6 @@ class FakeConnection(object):
 
 
 class FakeInstance(object):
+
     def __init__(self):
         self._state = power_state.NOSTATE
diff --git a/nova/virt/libvirt.qemu.xml.template b/nova/virt/libvirt.qemu.xml.template
deleted file mode 100644
index 2538b1ade..000000000
--- a/nova/virt/libvirt.qemu.xml.template
+++ /dev/null
@@ -1,33 +0,0 @@
-<domain type='%(type)s'>
-    <name>%(name)s</name>
-    <os>
-        <type>hvm</type>
-        <kernel>%(basepath)s/kernel</kernel>
-        <initrd>%(basepath)s/ramdisk</initrd>
-        <cmdline>root=/dev/vda1 console=ttyS0</cmdline>
-    </os>
-    <features>
-        <acpi/>
-    </features>
-    <memory>%(memory_kb)s</memory>
-    <vcpu>%(vcpus)s</vcpu>
-    <devices>
-        <disk type='file'>
-            <source file='%(basepath)s/disk'/>
-            <target dev='vda' bus='virtio'/>
-        </disk>
-        <interface type='bridge'>
-            <source bridge='%(bridge_name)s'/>
-            <mac address='%(mac_address)s'/>
-            <!--   <model type='virtio'/>  CANT RUN virtio network right now -->
-            <filterref filter="nova-instance-%(name)s">
-                <parameter name="IP" value="%(ip_address)s" />
-                <parameter name="DHCPSERVER" value="%(dhcp_server)s" />
-            </filterref>
-        </interface>
-        <serial type="file">
-            <source path='%(basepath)s/console.log'/>
-            <target port='1'/>
-        </serial>
-    </devices>
-</domain>
diff --git a/nova/virt/libvirt.rescue.qemu.xml.template b/nova/virt/libvirt.rescue.qemu.xml.template
deleted file mode 100644
index c0ffbdcee..000000000
--- a/nova/virt/libvirt.rescue.qemu.xml.template
+++ /dev/null
@@ -1,37 +0,0 @@
-<domain type='%(type)s'>
-    <name>%(name)s</name>
-    <os>
-        <type>hvm</type>
-        <kernel>%(basepath)s/rescue-kernel</kernel>
-        <initrd>%(basepath)s/rescue-ramdisk</initrd>
-        <cmdline>root=/dev/vda1 console=ttyS0</cmdline>
-    </os>
-    <features>
-        <acpi/>
-    </features>
-    <memory>%(memory_kb)s</memory>
-    <vcpu>%(vcpus)s</vcpu>
-    <devices>
-        <disk type='file'>
-            <source file='%(basepath)s/rescue-disk'/>
-            <target dev='vda' bus='virtio'/>
-        </disk>
-        <disk type='file'>
-            <source file='%(basepath)s/disk'/>
-            <target dev='vdb' bus='virtio'/>
-        </disk>
-        <interface type='bridge'>
-            <source bridge='%(bridge_name)s'/>
-            <mac address='%(mac_address)s'/>
-            <!--   <model type='virtio'/>  CANT RUN virtio network right now -->
-            <filterref filter="nova-instance-%(name)s">
-                <parameter name="IP" value="%(ip_address)s" />
-                <parameter name="DHCPSERVER" value="%(dhcp_server)s" />
-            </filterref>
-        </interface>
-        <serial type="file">
-            <source path='%(basepath)s/console.log'/>
-            <target port='1'/>
-        </serial>
-    </devices>
-</domain>
diff --git a/nova/virt/libvirt.rescue.uml.xml.template b/nova/virt/libvirt.rescue.uml.xml.template
deleted file mode 100644
index 836f47532..000000000
--- a/nova/virt/libvirt.rescue.uml.xml.template
+++ /dev/null
@@ -1,26 +0,0 @@
-<domain type='%(type)s'>
-    <name>%(name)s</name>
-    <memory>%(memory_kb)s</memory>
-    <os>
-        <type>%(type)s</type>
-        <kernel>/usr/bin/linux</kernel>
-        <root>/dev/ubda1</root>
-    </os>
-    <devices>
-        <disk type='file'>
-            <source file='%(basepath)s/rescue-disk'/>
-            <target dev='ubd0' bus='uml'/>
-        </disk>
-        <disk type='file'>
-            <source file='%(basepath)s/disk'/>
-            <target dev='ubd1' bus='uml'/>
-        </disk>
-        <interface type='bridge'>
-            <source bridge='%(bridge_name)s'/>
-            <mac address='%(mac_address)s'/>
-        </interface>
-        <console type="file">
-            <source path='%(basepath)s/console.log'/>
-        </console>
-    </devices>
-</domain>
diff --git a/nova/virt/libvirt.rescue.xen.xml.template b/nova/virt/libvirt.rescue.xen.xml.template
deleted file mode 100644
index 3b8d27237..000000000
--- a/nova/virt/libvirt.rescue.xen.xml.template
+++ /dev/null
@@ -1,34 +0,0 @@
-<domain type='%(type)s'>
-    <name>%(name)s</name>
-    <os>
-        <type>linux</type>
-        <kernel>%(basepath)s/kernel</kernel>
-        <initrd>%(basepath)s/ramdisk</initrd>
-        <root>/dev/xvda1</root>
-        <cmdline>ro</cmdline>
-    </os>
-    <features>
-        <acpi/>
-    </features>
-    <memory>%(memory_kb)s</memory>
-    <vcpu>%(vcpus)s</vcpu>
-    <devices>
-        <disk type='file'>
-            <source file='%(basepath)s/rescue-disk'/>
-            <target dev='sda' />
-        </disk>
-        <disk type='file'>
-            <source file='%(basepath)s/disk'/>
-            <target dev='sdb' />
-        </disk>
-        <interface type='bridge'>
-            <source bridge='%(bridge_name)s'/>
-            <mac address='%(mac_address)s'/>
-        </interface>
-        <console type="file">
-            <source path='%(basepath)s/console.log'/>
-            <target port='1'/>
-        </console>
-    </devices>
-</domain>
-
diff --git a/nova/virt/libvirt.uml.xml.template b/nova/virt/libvirt.uml.xml.template
deleted file mode 100644
index bb8b47911..000000000
--- a/nova/virt/libvirt.uml.xml.template
+++ /dev/null
@@ -1,26 +0,0 @@
-<domain type='%(type)s'>
-    <name>%(name)s</name>
-    <memory>%(memory_kb)s</memory>
-    <os>
-        <type>%(type)s</type>
-        <kernel>/usr/bin/linux</kernel>
-        <root>/dev/ubda1</root>
-    </os>
-    <devices>
-        <disk type='file'>
-            <source file='%(basepath)s/disk'/>
-            <target dev='ubd0' bus='uml'/>
-        </disk>
-        <interface type='bridge'>
-            <source bridge='%(bridge_name)s'/>
-            <mac address='%(mac_address)s'/>
-            <filterref filter="nova-instance-%(name)s">
-                <parameter name="IP" value="%(ip_address)s" />
-                <parameter name="DHCPSERVER" value="%(dhcp_server)s" />
-            </filterref>
-        </interface>
-        <console type="file">
-            <source path='%(basepath)s/console.log'/>
-        </console>
-    </devices>
-</domain>
diff --git a/nova/virt/libvirt.xen.xml.template b/nova/virt/libvirt.xen.xml.template
deleted file mode 100644
index 9677902c6..000000000
--- a/nova/virt/libvirt.xen.xml.template
+++ /dev/null
@@ -1,30 +0,0 @@
-<domain type='%(type)s'>
-    <name>%(name)s</name>
-    <os>
-        <type>linux</type>
-        <kernel>%(basepath)s/kernel</kernel>
-        <initrd>%(basepath)s/ramdisk</initrd>
-        <root>/dev/xvda1</root>
-        <cmdline>ro</cmdline>
-    </os>
-    <features>
-        <acpi/>
-    </features>
-    <memory>%(memory_kb)s</memory>
-    <vcpu>%(vcpus)s</vcpu>
-    <devices>
-        <disk type='file'>
-            <source file='%(basepath)s/disk'/>
-            <target dev='sda' />
-        </disk>
-        <interface type='bridge'>
-            <source bridge='%(bridge_name)s'/>
-            <mac address='%(mac_address)s'/>
-        </interface>
-        <console type="file">
-            <source path='%(basepath)s/console.log'/>
-            <target port='1'/>
-        </console>
-    </devices>
-</domain>
-
diff --git a/nova/virt/libvirt.xml.template b/nova/virt/libvirt.xml.template
new file mode 100644
index 000000000..13d087330
--- /dev/null
+++ b/nova/virt/libvirt.xml.template
@@ -0,0 +1,76 @@
+<domain type='${type}'>
+    <name>${name}</name>
+    <memory>${memory_kb}</memory>
+    <os>
+#if $type == 'uml'
+    #set $disk_prefix = 'ubd'
+    #set $disk_bus = 'uml'
+        <type>uml</type>
+        <kernel>/usr/bin/linux</kernel>
+        <root>/dev/ubda1</root>
+#else
+    #if $type == 'xen'
+        #set $disk_prefix = 'sd'
+        #set $disk_bus = 'scsi'
+            <type>linux</type>
+            <root>/dev/xvda1</root>
+    #else
+        #set $disk_prefix = 'vd'
+        #set $disk_bus = 'virtio'
+            <type>hvm</type>
+	#end if
+    #if $getVar('rescue', False)
+        <kernel>${basepath}/rescue-kernel</kernel>
+        <initrd>${basepath}/rescue-ramdisk</initrd>
+    #else
+        #if $getVar('kernel', None)
+            <kernel>${kernel}</kernel>
+            #if $type == 'xen'
+                <cmdline>ro</cmdline>
+            #else
+                <cmdline>root=/dev/vda1 console=ttyS0</cmdline>
+            #end if
+            #if $getVar('ramdisk', None)
+                <initrd>${ramdisk}</initrd>
+            #end if
+        #else
+            <boot dev="hd" />
+        #end if
+    #end if
+#end if
+    </os>
+    <features>
+        <acpi/>
+    </features>
+    <vcpu>${vcpus}</vcpu>
+    <devices>
+#if $getVar('rescue', False)
+        <disk type='file'>
+            <source file='${basepath}/rescue-disk'/>
+            <target dev='${disk_prefix}a' bus='${disk_bus}'/>
+        </disk>
+        <disk type='file'>
+            <source file='${basepath}/disk'/>
+            <target dev='${disk_prefix}b' bus='${disk_bus}'/>
+        </disk>
+#else
+        <disk type='file'>
+            <source file='${basepath}/disk'/>
+            <target dev='${disk_prefix}a' bus='${disk_bus}'/>
+        </disk>
+#end if
+        <interface type='bridge'>
+            <source bridge='${bridge_name}'/>
+            <mac address='${mac_address}'/>
+            <!--   <model type='virtio'/>  CANT RUN virtio network right now -->
+            <filterref filter="nova-instance-${name}">
+                <parameter name="IP" value="${ip_address}" />
+                <parameter name="DHCPSERVER" value="${dhcp_server}" />
+            </filterref>
+        </interface>
+        <serial type="file">
+            <source path='${basepath}/console.log'/>
+            <target port='1'/>
+        </serial>
+    </devices>
+</domain>
diff --git a/nova/virt/libvirt_conn.py b/nova/virt/libvirt_conn.py
index 5a8c71850..ad101db2a 100644
--- a/nova/virt/libvirt_conn.py
+++ b/nova/virt/libvirt_conn.py
@@ -27,12 +27,7 @@ Supports KVM, QEMU, UML, and XEN.
 :libvirt_type:  Libvirt domain type.  Can be kvm, qemu, uml, xen
                 (default: kvm).
 :libvirt_uri:  Override for the default libvirt URI (depends on libvirt_type).
-:libvirt_xml_template:  Libvirt XML Template (QEmu/KVM).
-:libvirt_xen_xml_template:  Libvirt XML Template (Xen).
-:libvirt_uml_xml_template:  Libvirt XML Template (User Mode Linux).
-:libvirt_rescue_xml_template:  XML template for rescue mode (KVM & QEMU).
-:libvirt_rescue_xen_xml_template:  XML templage for rescue mode (XEN).
-:libvirt_rescue_uml_xml_template:  XML template for rescue mode (UML).
+:libvirt_xml_template:  Libvirt XML Template.
 :rescue_image_id:  Rescue ami image (default: ami-rescue).
 :rescue_kernel_id:  Rescue aki image (default: aki-rescue).
 :rescue_ramdisk_id:  Rescue ari image (default: ari-rescue).
@@ -62,36 +57,20 @@ from nova.compute import instance_types
 from nova.compute import power_state
 from nova.virt import images
 
+from Cheetah.Template import Template
+
 libvirt = None
 libxml2 = None
 
 
 FLAGS = flags.FLAGS
-flags.DEFINE_string('libvirt_rescue_xml_template',
-                    utils.abspath('virt/libvirt.rescue.qemu.xml.template'),
-                    'Libvirt RESCUE XML Template for QEmu/KVM')
-flags.DEFINE_string('libvirt_rescue_xen_xml_template',
-                    utils.abspath('virt/libvirt.rescue.xen.xml.template'),
-                    'Libvirt RESCUE XML Template for xen')
-flags.DEFINE_string('libvirt_rescue_uml_xml_template',
-                    utils.abspath('virt/libvirt.rescue.uml.xml.template'),
-                    'Libvirt RESCUE XML Template for user-mode-linux')
 # TODO(vish): These flags should probably go into a shared location
 flags.DEFINE_string('rescue_image_id', 'ami-rescue', 'Rescue ami image')
 flags.DEFINE_string('rescue_kernel_id', 'aki-rescue', 'Rescue aki image')
 flags.DEFINE_string('rescue_ramdisk_id', 'ari-rescue', 'Rescue ari image')
 flags.DEFINE_string('libvirt_xml_template',
-                    utils.abspath('virt/libvirt.qemu.xml.template'),
-                    'Libvirt XML Template for QEmu/KVM')
-flags.DEFINE_string('libvirt_xen_xml_template',
-                    utils.abspath('virt/libvirt.xen.xml.template'),
-                    'Libvirt XML Template for Xen')
-flags.DEFINE_string('libvirt_uml_xml_template',
-                    utils.abspath('virt/libvirt.uml.xml.template'),
-                    'Libvirt XML Template for user-mode-linux')
-flags.DEFINE_string('injected_network_template',
-                    utils.abspath('virt/interfaces.template'),
-                    'Template file for injected network')
+                    utils.abspath('virt/libvirt.xml.template'),
+                    'Libvirt XML Template')
 flags.DEFINE_string('libvirt_type',
                     'kvm',
                     'Libvirt domain type (valid options are: '
@@ -118,13 +97,11 @@ def get_connection(read_only):
 
 
 class LibvirtConnection(object):
+
     def __init__(self, read_only):
-        (self.libvirt_uri,
-         template_file,
-         rescue_file) = self.get_uri_and_templates()
+        self.libvirt_uri = self.get_uri()
 
-        self.libvirt_xml = open(template_file).read()
-        self.rescue_xml = open(rescue_file).read()
+        self.libvirt_xml = open(FLAGS.libvirt_xml_template).read()
         self._wrapped_conn = None
         self.read_only = read_only
 
@@ -147,20 +124,14 @@ class LibvirtConnection(object):
                 return False
             raise
 
-    def get_uri_and_templates(self):
+    def get_uri(self):
         if FLAGS.libvirt_type == 'uml':
             uri = FLAGS.libvirt_uri or 'uml:///system'
-            template_file = FLAGS.libvirt_uml_xml_template
-            rescue_file = FLAGS.libvirt_rescue_uml_xml_template
         elif FLAGS.libvirt_type == 'xen':
             uri = FLAGS.libvirt_uri or 'xen:///'
-            template_file = FLAGS.libvirt_xen_xml_template
-            rescue_file = FLAGS.libvirt_rescue_xen_xml_template
         else:
             uri = FLAGS.libvirt_uri or 'qemu:///system'
-            template_file = FLAGS.libvirt_xml_template
-            rescue_file = FLAGS.libvirt_rescue_xml_template
-        return uri, template_file, rescue_file
+        return uri
 
     def _connect(self, uri, read_only):
         auth = [[libvirt.VIR_CRED_AUTHNAME, libvirt.VIR_CRED_NOECHOPROMPT],
@@ -291,6 +262,14 @@ class LibvirtConnection(object):
         return timer.start(interval=0.5, now=True)
 
     @exception.wrap_exception
+    def pause(self, instance, callback):
+        raise exception.APIError("pause not supported for libvirt.")
+
+    @exception.wrap_exception
+    def unpause(self, instance, callback):
+        raise exception.APIError("unpause not supported for libvirt.")
+
+    @exception.wrap_exception
     def rescue(self, instance):
         self.destroy(instance, False)
 
@@ -433,18 +412,28 @@ class LibvirtConnection(object):
         if not os.path.exists(basepath('disk')):
             images.fetch(inst.image_id, basepath('disk-raw'), user,
                          project)
-        if not os.path.exists(basepath('kernel')):
-            images.fetch(inst.kernel_id, basepath('kernel'), user,
-                         project)
-        if not os.path.exists(basepath('ramdisk')):
-            images.fetch(inst.ramdisk_id, basepath('ramdisk'), user,
-                         project)
+
+        if inst['kernel_id']:
+            if not os.path.exists(basepath('kernel')):
+                images.fetch(inst['kernel_id'], basepath('kernel'),
+                             user, project)
+            if inst['ramdisk_id']:
+                if not os.path.exists(basepath('ramdisk')):
+                    images.fetch(inst['ramdisk_id'], basepath('ramdisk'),
+                                 user, project)
 
         def execute(cmd, process_input=None, check_exit_code=True):
             return utils.execute(cmd=cmd,
                                  process_input=process_input,
                                  check_exit_code=check_exit_code)
 
+        # For now, we assume that if we're not using a kernel, we're using a
+        # partitioned disk image where the target partition is the first
+        # partition
+        target_partition = None
+        if not inst['kernel_id']:
+            target_partition = "1"
+
         key = str(inst['key_data'])
         net = None
         network_ref = db.network_get_by_instance(context.get_admin_context(),
@@ -464,12 +453,20 @@ class LibvirtConnection(object):
                     inst['name'], inst.image_id)
             if net:
                 logging.info('instance %s: injecting net into image %s',
-                    inst['name'], inst.image_id)
-            disk.inject_data(basepath('disk-raw'), key, net,
-                             execute=execute)
-
-        if os.path.exists(basepath('disk')):
-            utils.execute('rm -f %s' % basepath('disk'))
+                             inst['name'], inst.image_id)
+            try:
+                disk.inject_data(basepath('disk-raw'), key, net,
+                                 partition=target_partition,
+                                 execute=execute)
+            except Exception as e:
+                # This could be a windows image, or a vmdk format disk
+                logging.warn('instance %s: ignoring error injecting data'
+                             ' into image %s (%s)',
+                             inst['name'], inst.image_id, e)
+
+        if inst['kernel_id']:
+            if os.path.exists(basepath('disk')):
+                utils.execute('rm -f %s' % basepath('disk'))
 
         local_bytes = (instance_types.INSTANCE_TYPES[inst.instance_type]
                                                     ['local_gb']
@@ -478,8 +475,13 @@ class LibvirtConnection(object):
         resize = True
         if inst['instance_type'] == 'm1.tiny' or prefix == 'rescue-':
             resize = False
-        disk.partition(basepath('disk-raw'), basepath('disk'),
-                       local_bytes, resize, execute=execute)
+
+        if inst['kernel_id']:
+            disk.partition(basepath('disk-raw'), basepath('disk'),
+                           local_bytes, resize, execute=execute)
+        else:
+            os.rename(basepath('disk-raw'), basepath('disk'))
+            disk.extend(basepath('disk'), local_bytes, execute=execute)
 
         if FLAGS.libvirt_type == 'uml':
             utils.execute('sudo chown root %s' % basepath('disk'))
@@ -505,14 +507,21 @@ class LibvirtConnection(object):
                     'bridge_name': network['bridge'],
                     'mac_address': instance['mac_address'],
                     'ip_address': ip_address,
-                    'dhcp_server': dhcp_server}
-        if rescue:
-            libvirt_xml = self.rescue_xml % xml_info
-        else:
-            libvirt_xml = self.libvirt_xml % xml_info
+                    'dhcp_server': dhcp_server,
+                    'rescue': rescue}
+        if not rescue:
+            if instance['kernel_id']:
+                xml_info['kernel'] = xml_info['basepath'] + "/kernel"
+
+            if instance['ramdisk_id']:
+                xml_info['ramdisk'] = xml_info['basepath'] + "/ramdisk"
+
+            xml_info['disk'] = xml_info['basepath'] + "/disk"
+
+        xml = str(Template(self.libvirt_xml, searchList=[xml_info]))
         logging.debug('instance %s: finished toXML method', instance['name'])
 
-        return libvirt_xml
+        return xml
 
     def get_info(self, instance_name):
         try:
diff --git a/nova/virt/xenapi/network_utils.py b/nova/virt/xenapi/network_utils.py
index e783120fe..3084d8103 100644
--- a/nova/virt/xenapi/network_utils.py
+++ b/nova/virt/xenapi/network_utils.py
@@ -28,6 +28,7 @@ class NetworkHelper(HelperBase):
     """
     The class that wraps the helper methods together.
     """
+
     def __init__(self):
         super(NetworkHelper, self).__init__()
 
diff --git a/nova/virt/xenapi/vm_utils.py b/nova/virt/xenapi/vm_utils.py
index 911fcc9b2..e34460245 100644
--- a/nova/virt/xenapi/vm_utils.py
+++ b/nova/virt/xenapi/vm_utils.py
@@ -46,6 +46,7 @@ class VMHelper(HelperBase):
     """
     The class that wraps the helper methods together.
     """
+
     def __init__(self):
         super(VMHelper, self).__init__()
 
diff --git a/nova/virt/xenapi/vmops.py b/nova/virt/xenapi/vmops.py
index aa3a3ae53..e6e4f67fa 100644
--- a/nova/virt/xenapi/vmops.py
+++ b/nova/virt/xenapi/vmops.py
@@ -35,6 +35,7 @@ class VMOps(object):
     """
     Management class for VM-related tasks
     """
+
     def __init__(self, session):
         self.XenAPI = session.get_imported_xenapi()
         self._session = session
@@ -139,6 +140,32 @@ class VMOps(object):
         except self.XenAPI.Failure, exc:
             logging.warn(exc)
 
+    def _wait_with_callback(self, task, callback):
+        ret = None
+        try:
+            ret = self._session.wait_for_task(task)
+        except XenAPI.Failure, exc:
+            logging.warn(exc)
+        callback(ret)
+
+    def pause(self, instance, callback):
+        """ Pause VM instance """
+        instance_name = instance.name
+        vm = VMHelper.lookup(self._session, instance_name)
+        if vm is None:
+            raise Exception('instance not present %s' % instance_name)
+        task = self._session.call_xenapi('Async.VM.pause', vm)
+        self._wait_with_callback(task, callback)
+
+    def unpause(self, instance, callback):
+        """ Unpause VM instance """
+        instance_name = instance.name
+        vm = VMHelper.lookup(self._session, instance_name)
+        if vm is None:
+            raise Exception('instance not present %s' % instance_name)
+        task = self._session.call_xenapi('Async.VM.unpause', vm)
+        self._wait_with_callback(task, callback)
+
     def get_info(self, instance_id):
         """ Return data about VM instance """
         vm = VMHelper.lookup(self._session, instance_id)
diff --git a/nova/virt/xenapi/volume_utils.py b/nova/virt/xenapi/volume_utils.py
index 5366078ce..9f8ff3b98 100644
--- a/nova/virt/xenapi/volume_utils.py
+++ b/nova/virt/xenapi/volume_utils.py
@@ -25,6 +25,7 @@ import logging
 
 from nova import db
 from nova import context
+from nova import exception
 from nova import flags
 from nova import utils
 from nova.virt.xenapi import HelperBase
@@ -248,17 +249,20 @@ def _get_target(volume_id):
     """
     volume_ref = db.volume_get_by_ec2_id(context.get_admin_context(),
                                          volume_id)
-
-    (r, _e) = utils.execute("sudo iscsiadm -m discovery -t "
+    result = (None, None)
+    try:
+        (r, _e) = utils.execute("sudo iscsiadm -m discovery -t "
                                      "sendtargets -p %s" %
                                      volume_ref['host'])
-    targets = r.splitlines()
-    if len(_e) == 0 and len(targets) == 1:
-        for target in targets:
-            if volume_id in target:
-                (location, _sep, iscsi_name) = target.partition(" ")
-                break
-        iscsi_portal = location.split(",")[0]
-        return (iscsi_name, iscsi_portal)
+    except exception.ProcessExecutionError, exc:
+        logging.warn(exc)
     else:
-        return (None, None)
+        targets = r.splitlines()
+        if len(_e) == 0 and len(targets) == 1:
+            for target in targets:
+                if volume_id in target:
+                    (location, _sep, iscsi_name) = target.partition(" ")
+                    break
+            iscsi_portal = location.split(",")[0]
+            result = (iscsi_name, iscsi_portal)
+    return result
diff --git a/nova/virt/xenapi/volumeops.py b/nova/virt/xenapi/volumeops.py
index 9dbb1bb14..7a6f3b090 100644
--- a/nova/virt/xenapi/volumeops.py
+++ b/nova/virt/xenapi/volumeops.py
@@ -28,6 +28,7 @@ class VolumeOps(object):
     """
     Management class for Volume-related tasks
     """
+
     def __init__(self, session):
         self.XenAPI = session.get_imported_xenapi()
         self._session = session
diff --git a/nova/virt/xenapi_conn.py b/nova/virt/xenapi_conn.py
index 2a8614cfd..c04ec8458 100644
--- a/nova/virt/xenapi_conn.py
+++ b/nova/virt/xenapi_conn.py
@@ -108,6 +108,7 @@ def get_connection(_):
 
 class XenAPIConnection(object):
     """ A connection to XenServer or Xen Cloud Platform """
+
     def __init__(self, url, user, pw):
         session = XenAPISession(url, user, pw)
         self._vmops = VMOps(session)
@@ -129,6 +130,14 @@ class XenAPIConnection(object):
         """ Destroy VM instance """
         self._vmops.destroy(instance)
 
+    def pause(self, instance, callback):
+        """ Pause VM instance """
+        self._vmops.pause(instance, callback)
+
+    def unpause(self, instance, callback):
+        """ Unpause paused VM instance """
+        self._vmops.unpause(instance, callback)
+
     def get_info(self, instance_id):
         """ Return data about VM instance """
         return self._vmops.get_info(instance_id)
@@ -154,6 +163,7 @@ class XenAPIConnection(object):
 
 class XenAPISession(object):
     """ The session to invoke XenAPI SDK calls """
+
     def __init__(self, url, user, pw):
         self.XenAPI = self.get_imported_xenapi()
         self._session = self._create_session(url)