X-Git-Url: https://code.grnet.gr/git/ganeti-local/blobdiff_plain/afdc3985644be8d2b91d9f0e37dfda391a30d036..b6b45e0d6251cd870658be36004ce4116f4a63c6:/lib/backend.py

diff --git a/lib/backend.py b/lib/backend.py
index 886ba27..75457e3 100644
--- a/lib/backend.py
+++ b/lib/backend.py
@@ -19,7 +19,12 @@
 # 02110-1301, USA.
 
 
-"""Functions used by the node daemon"""
+"""Functions used by the node daemon
+
+@var _ALLOWED_UPLOAD_FILES: denotes which files are accepted in
+     the L{UploadFile} function
+
+"""
 
 
 import os
@@ -46,6 +51,9 @@ from ganeti import objects
 from ganeti import ssconf
 
 
+_BOOT_ID_PATH = "/proc/sys/kernel/random/boot_id"
+
+
 class RPCFail(Exception):
   """Class denoting RPC failure.
 
@@ -53,6 +61,7 @@ class RPCFail(Exception):
 
   """
 
+
 def _Fail(msg, *args, **kwargs):
   """Log an error and the raise an RPCFail exception.
 
@@ -145,6 +154,32 @@ def _CleanDirectory(path, exclude=None):
       utils.RemoveFile(full_name)
 
 
+def _BuildUploadFileList():
+  """Build the list of allowed upload files.
+
+  This is abstracted so that it's built only once at module import time.
+
+  """
+  allowed_files = set([
+    constants.CLUSTER_CONF_FILE,
+    constants.ETC_HOSTS,
+    constants.SSH_KNOWN_HOSTS_FILE,
+    constants.VNC_PASSWORD_FILE,
+    constants.RAPI_CERT_FILE,
+    constants.RAPI_USERS_FILE,
+    constants.HMAC_CLUSTER_KEY,
+    ])
+
+  for hv_name in constants.HYPER_TYPES:
+    hv_class = hypervisor.GetHypervisorClass(hv_name)
+    allowed_files.update(hv_class.GetAncillaryFiles())
+
+  return frozenset(allowed_files)
+
+
+_ALLOWED_UPLOAD_FILES = _BuildUploadFileList()
+
+
 def JobQueuePurge():
   """Removes job queue files and archived jobs.
 
@@ -154,7 +189,6 @@ def JobQueuePurge():
   """
   _CleanDirectory(constants.QUEUE_DIR, exclude=[constants.JOB_QUEUE_LOCK_FILE])
   _CleanDirectory(constants.JOB_QUEUE_ARCHIVE_DIR)
-  return True, None
 
 
 def GetMasterInfo():
@@ -164,7 +198,7 @@ def GetMasterInfo():
   for consumption here or from the node daemon.
 
   @rtype: tuple
-  @return: True, (master_netdev, master_ip, master_name) in case of success
+  @return: master_netdev, master_ip, master_name
   @raise RPCFail: in case of errors
 
   """
@@ -174,11 +208,11 @@ def GetMasterInfo():
     master_ip = cfg.GetMasterIP()
     master_node = cfg.GetMasterNode()
   except errors.ConfigurationError, err:
-    _Fail("Cluster configuration incomplete", exc=True)
-  return True, (master_netdev, master_ip, master_node)
+    _Fail("Cluster configuration incomplete: %s", err, exc=True)
+  return (master_netdev, master_ip, master_node)
 
 
-def StartMaster(start_daemons):
+def StartMaster(start_daemons, no_voting):
   """Activate local node as master node.
 
   The function will always try activate the IP address of the master
@@ -186,15 +220,18 @@ def StartMaster(start_daemons):
   based on the start_daemons parameter.
 
   @type start_daemons: boolean
-  @param start_daemons: whther to also start the master
+  @param start_daemons: whether to also start the master
       daemons (ganeti-masterd and ganeti-rapi)
+  @type no_voting: boolean
+  @param no_voting: whether to start ganeti-masterd without a node vote
+      (if start_daemons is True), but still non-interactively
   @rtype: None
 
   """
   # GetMasterInfo will raise an exception if not able to return data
-  master_netdev, master_ip, _ = GetMasterInfo()[1]
+  master_netdev, master_ip, _ = GetMasterInfo()
 
-  payload = []
+  err_msgs = []
   if utils.TcpPing(master_ip, constants.DEFAULT_NODED_PORT):
     if utils.OwnIpAddress(master_ip):
       # we already have the ip:
@@ -202,7 +239,7 @@ def StartMaster(start_daemons):
     else:
       msg = "Someone else has the master ip, not activating"
       logging.error(msg)
-      payload.append(msg)
+      err_msgs.append(msg)
   else:
     result = utils.RunCmd(["ip", "address", "add", "%s/32" % master_ip,
                            "dev", master_netdev, "label",
@@ -210,7 +247,7 @@ def StartMaster(start_daemons):
     if result.failed:
       msg = "Can't activate master IP: %s" % result.output
       logging.error(msg)
-      payload.append(msg)
+      err_msgs.append(msg)
 
     result = utils.RunCmd(["arping", "-q", "-U", "-c 3", "-I", master_netdev,
                            "-s", master_ip, master_ip])
@@ -218,17 +255,24 @@ def StartMaster(start_daemons):
 
   # and now start the master and rapi daemons
   if start_daemons:
-    for daemon in 'ganeti-masterd', 'ganeti-rapi':
-      result = utils.RunCmd([daemon])
+    daemons_params = {
+        'ganeti-masterd': [],
+        'ganeti-rapi': [],
+        }
+    if no_voting:
+      daemons_params['ganeti-masterd'].append('--no-voting')
+      daemons_params['ganeti-masterd'].append('--yes-do-it')
+    for daemon in daemons_params:
+      cmd = [daemon]
+      cmd.extend(daemons_params[daemon])
+      result = utils.RunCmd(cmd)
       if result.failed:
         msg = "Can't start daemon %s: %s" % (daemon, result.output)
         logging.error(msg)
-        payload.append(msg)
+        err_msgs.append(msg)
 
-  if payload:
-    _Fail("; ".join(payload))
-
-  return True, None
+  if err_msgs:
+    _Fail("; ".join(err_msgs))
 
 
 def StopMaster(stop_daemons):
@@ -248,7 +292,7 @@ def StopMaster(stop_daemons):
   # need to decide in which case we fail the RPC for this
 
   # GetMasterInfo will raise an exception if not able to return data
-  master_netdev, master_ip, _ = GetMasterInfo()[1]
+  master_netdev, master_ip, _ = GetMasterInfo()
 
   result = utils.RunCmd(["ip", "address", "del", "%s/32" % master_ip,
                          "dev", master_netdev])
@@ -258,11 +302,9 @@ def StopMaster(stop_daemons):
 
   if stop_daemons:
     # stop/kill the rapi and the master daemon
-    for daemon in constants.RAPI_PID, constants.MASTERD_PID:
+    for daemon in constants.RAPI, constants.MASTERD:
       utils.KillProcess(utils.ReadPidFile(utils.DaemonPidFileName(daemon)))
 
-  return True, None
-
 
 def AddNode(dsa, dsapub, rsa, rsapub, sshkey, sshpub):
   """Joins this node to the cluster.
@@ -308,8 +350,6 @@ def AddNode(dsa, dsapub, rsa, rsapub, sshkey, sshpub):
 
   utils.RunCmd([constants.SSH_INITD_SCRIPT, "restart"])
 
-  return (True, "Node added successfully")
-
 
 def LeaveCluster():
   """Cleans up and remove the current node.
@@ -328,23 +368,31 @@ def LeaveCluster():
   try:
     priv_key, pub_key, auth_keys = ssh.GetUserFiles(constants.GANETI_RUNAS)
 
-    f = open(pub_key, 'r')
-    try:
-      utils.RemoveAuthorizedKey(auth_keys, f.read(8192))
-    finally:
-      f.close()
+    utils.RemoveAuthorizedKey(auth_keys, utils.ReadFile(pub_key))
 
     utils.RemoveFile(priv_key)
     utils.RemoveFile(pub_key)
   except errors.OpExecError:
     logging.exception("Error while processing ssh files")
 
+  try:
+    utils.RemoveFile(constants.HMAC_CLUSTER_KEY)
+    utils.RemoveFile(constants.RAPI_CERT_FILE)
+    utils.RemoveFile(constants.SSL_CERT_FILE)
+  except:
+    logging.exception("Error while removing cluster secrets")
+
+  confd_pid = utils.ReadPidFile(utils.DaemonPidFileName(constants.CONFD))
+
+  if confd_pid:
+    utils.KillProcess(confd_pid, timeout=2)
+
   # Raise a custom exception (handled in ganeti-noded)
   raise errors.QuitGanetiException(True, 'Shutdown scheduled')
 
 
 def GetNodeInfo(vgname, hypervisor_type):
-  """Gives back a hash with different informations about the node.
+  """Gives back a hash with different information about the node.
 
   @type vgname: C{string}
   @param vgname: the name of the volume group to ask for disk space information
@@ -370,13 +418,9 @@ def GetNodeInfo(vgname, hypervisor_type):
   if hyp_info is not None:
     outputarray.update(hyp_info)
 
-  f = open("/proc/sys/kernel/random/boot_id", 'r')
-  try:
-    outputarray["bootid"] = f.read(128).rstrip("\n")
-  finally:
-    f.close()
+  outputarray["bootid"] = utils.ReadFile(_BOOT_ID_PATH, size=128).rstrip("\n")
 
-  return True, outputarray
+  return outputarray
 
 
 def VerifyNode(what, cluster_name):
@@ -440,7 +484,7 @@ def VerifyNode(what, cluster_name):
       tmp[my_name] = ("Can't find my own primary/secondary IP"
                       " in the node list")
     else:
-      port = utils.GetNodeDaemonPort()
+      port = utils.GetDaemonPort(constants.NODED)
       for name, pip, sip in what[constants.NV_NODENETTEST]:
         fail = []
         if not utils.TcpPing(pip, port, source=my_pip):
@@ -478,7 +522,7 @@ def VerifyNode(what, cluster_name):
       used_minors = str(err)
     result[constants.NV_DRBDLIST] = used_minors
 
-  return True, result
+  return result
 
 
 def GetVolumeList(vg_name):
@@ -515,6 +559,11 @@ def GetVolumeList(vg_name):
     name, size, attr = match.groups()
     inactive = attr[4] == '-'
     online = attr[5] == 'o'
+    virtual = attr[0] == 'v'
+    if virtual:
+      # we don't want to report such volumes as existing, since they
+      # don't really hold data
+      continue
     lvs[name] = (size, inactive, online)
 
   return lvs
@@ -528,7 +577,7 @@ def ListVolumeGroups():
       size of the volume
 
   """
-  return True, utils.ListVolumeGroups()
+  return utils.ListVolumeGroups()
 
 
 def NodeVolumes():
@@ -571,9 +620,8 @@ def NodeVolumes():
       'vg': line[3].strip(),
     }
 
-  return True, [map_line(line.split('|'))
-                for line in result.stdout.splitlines()
-                if line.count('|') >= 3]
+  return [map_line(line.split('|')) for line in result.stdout.splitlines()
+          if line.count('|') >= 3]
 
 
 def BridgesExist(bridges_list):
@@ -591,8 +639,6 @@ def BridgesExist(bridges_list):
   if missing:
     _Fail("Missing bridges %s", ", ".join(missing))
 
-  return True, None
-
 
 def GetInstanceList(hypervisor_list):
   """Provides a list of instances.
@@ -619,7 +665,7 @@ def GetInstanceList(hypervisor_list):
 
 
 def GetInstanceInfo(instance, hname):
-  """Gives back the informations about an instance as a dictionary.
+  """Gives back the information about an instance as a dictionary.
 
   @type instance: string
   @param instance: the instance name
@@ -641,7 +687,7 @@ def GetInstanceInfo(instance, hname):
     output['state'] = iinfo[4]
     output['time'] = iinfo[5]
 
-  return True, output
+  return output
 
 
 def GetInstanceMigratable(instance):
@@ -666,8 +712,6 @@ def GetInstanceMigratable(instance):
     if not os.path.islink(link_name):
       _Fail("Instance %s was not restarted since ganeti 1.2.5", iname)
 
-  return True, None
-
 
 def GetAllInstancesInfo(hypervisor_list):
   """Gather data about all instances.
@@ -692,7 +736,7 @@ def GetAllInstancesInfo(hypervisor_list):
   for hname in hypervisor_list:
     iinfo = hypervisor.GetHypervisor(hname).GetAllInstancesInfo()
     if iinfo:
-      for name, inst_id, memory, vcpus, state, times in iinfo:
+      for name, _, memory, vcpus, state, times in iinfo:
         value = {
           'memory': memory,
           'vcpus': vcpus,
@@ -709,7 +753,7 @@ def GetAllInstancesInfo(hypervisor_list):
                     " with different parameters", name)
         output[name] = value
 
-  return True, output
+  return output
 
 
 def InstanceOsAdd(instance, reinstall):
@@ -719,14 +763,12 @@ def InstanceOsAdd(instance, reinstall):
   @param instance: Instance whose OS is to be installed
   @type reinstall: boolean
   @param reinstall: whether this is an instance reinstall
-  @rtype: boolean
-  @return: the success of the operation
+  @rtype: None
 
   """
   inst_os = OSFromDisk(instance.os)
 
-
-  create_env = OSEnvironment(instance)
+  create_env = OSEnvironment(instance, inst_os)
   if reinstall:
     create_env['INSTANCE_REINSTALL'] = "1"
 
@@ -744,8 +786,6 @@ def InstanceOsAdd(instance, reinstall):
     _Fail("OS create script failed (%s), last lines in the"
           " log file:\n%s", result.fail_reason, "\n".join(lines), log=False)
 
-  return (True, "Successfully installed")
-
 
 def RunRenameInstance(instance, old_name):
   """Run the OS rename script for an instance.
@@ -760,7 +800,7 @@ def RunRenameInstance(instance, old_name):
   """
   inst_os = OSFromDisk(instance.os)
 
-  rename_env = OSEnvironment(instance)
+  rename_env = OSEnvironment(instance, inst_os)
   rename_env['OLD_INSTANCE_NAME'] = old_name
 
   logfile = "%s/rename-%s-%s-%s-%d.log" % (constants.LOG_OS_DIR, instance.os,
@@ -778,11 +818,9 @@ def RunRenameInstance(instance, old_name):
     _Fail("OS rename script failed (%s), last lines in the"
           " log file:\n%s", result.fail_reason, "\n".join(lines), log=False)
 
-  return (True, "Rename successful")
-
 
 def _GetVGInfo(vg_name):
-  """Get informations about the volume group.
+  """Get information about the volume group.
 
   @type vg_name: str
   @param vg_name: the volume group which we query
@@ -814,7 +852,7 @@ def _GetVGInfo(vg_name):
         "pv_count": int(valarr[2]),
         }
     except ValueError, err:
-      logging.exception("Fail to parse vgs output")
+      logging.exception("Fail to parse vgs output: %s", err)
   else:
     logging.error("vgs output has the wrong number of fields (expected"
                   " three): %s", str(valarr))
@@ -858,7 +896,7 @@ def _RemoveBlockDevLinks(instance_name, disks):
   """Remove the block device symlinks belonging to the given instance.
 
   """
-  for idx, disk in enumerate(disks):
+  for idx, _ in enumerate(disks):
     link_name = _GetBlockDevSymlinkPath(instance_name, idx)
     if os.path.islink(link_name):
       try:
@@ -902,14 +940,14 @@ def StartInstance(instance):
 
   @type instance: L{objects.Instance}
   @param instance: the instance object
-  @rtype: boolean
-  @return: whether the startup was successful or not
+  @rtype: None
 
   """
   running_instances = GetInstanceList([instance.hypervisor])
 
   if instance.name in running_instances:
-    return (True, "Already running")
+    logging.info("Instance %s already running, not starting", instance.name)
+    return
 
   try:
     block_devices = _GatherAndLinkBlockDevs(instance)
@@ -921,8 +959,6 @@ def StartInstance(instance):
     _RemoveBlockDevLinks(instance.name, instance.disks)
     _Fail("Hypervisor error: %s", err, exc=True)
 
-  return (True, "Instance started successfully")
-
 
 def InstanceShutdown(instance):
   """Shut an instance down.
@@ -931,46 +967,44 @@ def InstanceShutdown(instance):
 
   @type instance: L{objects.Instance}
   @param instance: the instance object
-  @rtype: boolean
-  @return: whether the startup was successful or not
+  @rtype: None
 
   """
   hv_name = instance.hypervisor
   running_instances = GetInstanceList([hv_name])
+  iname = instance.name
 
-  if instance.name not in running_instances:
-    return (True, "Instance already stopped")
+  if iname not in running_instances:
+    logging.info("Instance %s not running, doing nothing", iname)
+    return
 
   hyper = hypervisor.GetHypervisor(hv_name)
   try:
     hyper.StopInstance(instance)
   except errors.HypervisorError, err:
-    _Fail("Failed to stop instance %s: %s", instance.name, err)
+    _Fail("Failed to stop instance %s: %s", iname, err)
 
   # test every 10secs for 2min
 
   time.sleep(1)
-  for dummy in range(11):
+  for _ in range(11):
     if instance.name not in GetInstanceList([hv_name]):
       break
     time.sleep(10)
   else:
     # the shutdown did not succeed
-    logging.error("Shutdown of '%s' unsuccessful, using destroy",
-                  instance.name)
+    logging.error("Shutdown of '%s' unsuccessful, using destroy", iname)
 
     try:
       hyper.StopInstance(instance, force=True)
     except errors.HypervisorError, err:
-      _Fail("Failed to force stop instance %s: %s", instance.name, err)
+      _Fail("Failed to force stop instance %s: %s", iname, err)
 
     time.sleep(1)
     if instance.name in GetInstanceList([hv_name]):
-      _Fail("Could not shutdown instance %s even by destroy", instance.name)
-
-  _RemoveBlockDevLinks(instance.name, instance.disks)
+      _Fail("Could not shutdown instance %s even by destroy", iname)
 
-  return (True, "Instance has been shutdown successfully")
+  _RemoveBlockDevLinks(iname, instance.disks)
 
 
 def InstanceReboot(instance, reboot_type):
@@ -985,11 +1019,11 @@ def InstanceReboot(instance, reboot_type):
         instance OS, do not recreate the VM
       - L{constants.INSTANCE_REBOOT_HARD}: tear down and
         restart the VM (at the hypervisor level)
-      - the other reboot type (L{constants.INSTANCE_REBOOT_HARD})
-        is not accepted here, since that mode is handled
-        differently
-  @rtype: boolean
-  @return: the success of the operation
+      - the other reboot type (L{constants.INSTANCE_REBOOT_FULL}) is
+        not accepted here, since that mode is handled differently, in
+        cmdlib, and translates into full stop and start of the
+        instance (instead of a call_instance_reboot RPC)
+  @rtype: None
 
   """
   running_instances = GetInstanceList([instance.hypervisor])
@@ -1005,17 +1039,13 @@ def InstanceReboot(instance, reboot_type):
       _Fail("Failed to soft reboot instance %s: %s", instance.name, err)
   elif reboot_type == constants.INSTANCE_REBOOT_HARD:
     try:
-      stop_result = InstanceShutdown(instance)
-      if not stop_result[0]:
-        return stop_result
+      InstanceShutdown(instance)
       return StartInstance(instance)
     except errors.HypervisorError, err:
       _Fail("Failed to hard reboot instance %s: %s", instance.name, err)
   else:
     _Fail("Invalid reboot_type received: %s", reboot_type)
 
-  return (True, "Reboot successful")
-
 
 def MigrationInfo(instance):
   """Gather information about an instance to be migrated.
@@ -1029,7 +1059,7 @@ def MigrationInfo(instance):
     info = hyper.MigrationInfo(instance)
   except errors.HypervisorError, err:
     _Fail("Failed to fetch migration information: %s", err, exc=True)
-  return (True, info)
+  return info
 
 
 def AcceptInstance(instance, info, target):
@@ -1048,7 +1078,6 @@ def AcceptInstance(instance, info, target):
     hyper.AcceptInstance(instance, info, target)
   except errors.HypervisorError, err:
     _Fail("Failed to accept instance: %s", err, exc=True)
-  return (True, "Accept successfull")
 
 
 def FinalizeMigration(instance, info, success):
@@ -1067,7 +1096,6 @@ def FinalizeMigration(instance, info, success):
     hyper.FinalizeMigration(instance, info, success)
   except errors.HypervisorError, err:
     _Fail("Failed to finalize migration: %s", err, exc=True)
-  return (True, "Migration Finalized")
 
 
 def MigrateInstance(instance, target, live):
@@ -1092,7 +1120,6 @@ def MigrateInstance(instance, target, live):
     hyper.MigrateInstance(instance.name, target, live)
   except errors.HypervisorError, err:
     _Fail("Failed to migrate instance: %s", err, exc=True)
-  return (True, "Migration successfull")
 
 
 def BlockdevCreate(disk, size, owner, on_primary, info):
@@ -1133,7 +1160,7 @@ def BlockdevCreate(disk, size, owner, on_primary, info):
       clist.append(crdev)
 
   try:
-    device = bdev.Create(disk.dev_type, disk.physical_id, clist, size)
+    device = bdev.Create(disk.dev_type, disk.physical_id, clist, disk.size)
   except errors.BlockDeviceError, err:
     _Fail("Can't create block device: %s", err)
 
@@ -1153,8 +1180,7 @@ def BlockdevCreate(disk, size, owner, on_primary, info):
 
   device.SetInfo(info)
 
-  physical_id = device.unique_id
-  return True, physical_id
+  return device.unique_id
 
 
 def BlockdevRemove(disk):
@@ -1169,7 +1195,6 @@ def BlockdevRemove(disk):
 
   """
   msgs = []
-  result = True
   try:
     rdev = _RecursiveFindBD(disk)
   except errors.BlockDeviceError, err:
@@ -1182,22 +1207,19 @@ def BlockdevRemove(disk):
       rdev.Remove()
     except errors.BlockDeviceError, err:
       msgs.append(str(err))
-      result = False
-    if result:
+    if not msgs:
       DevCacheManager.RemoveCache(r_path)
 
   if disk.children:
     for child in disk.children:
-      c_status, c_msg = BlockdevRemove(child)
-      result = result and c_status
-      if c_msg: # not an empty message
-        msgs.append(c_msg)
+      try:
+        BlockdevRemove(child)
+      except RPCFail, err:
+        msgs.append(str(err))
 
-  if not result:
+  if msgs:
     _Fail("; ".join(msgs))
 
-  return True, None
-
 
 def _RecursiveAssembleBD(disk, owner, as_primary):
   """Activate a block device for an instance.
@@ -1240,7 +1262,7 @@ def _RecursiveAssembleBD(disk, owner, as_primary):
       children.append(cdev)
 
   if as_primary or disk.AssembleOnSecondary():
-    r_dev = bdev.Assemble(disk.dev_type, disk.physical_id, children)
+    r_dev = bdev.Assemble(disk.dev_type, disk.physical_id, children, disk.size)
     r_dev.SetSyncSpeed(constants.SYNC_SPEED)
     result = r_dev
     if as_primary or disk.OpenOnSecondary():
@@ -1270,13 +1292,13 @@ def BlockdevAssemble(disk, owner, as_primary):
   except errors.BlockDeviceError, err:
     _Fail("Error while assembling disk: %s", err, exc=True)
 
-  return True, result
+  return result
 
 
 def BlockdevShutdown(disk):
   """Shut down a block device.
 
-  First, if the device is assembled (Attach() is successfull), then
+  First, if the device is assembled (Attach() is successful), then
   the device is shutdown. Then the children of the device are
   shutdown.
 
@@ -1287,12 +1309,10 @@ def BlockdevShutdown(disk):
   @type disk: L{objects.Disk}
   @param disk: the description of the disk we should
       shutdown
-  @rtype: boolean
-  @return: the success of the operation
+  @rtype: None
 
   """
   msgs = []
-  result = True
   r_dev = _RecursiveFindBD(disk)
   if r_dev is not None:
     r_path = r_dev.dev_path
@@ -1301,18 +1321,16 @@ def BlockdevShutdown(disk):
       DevCacheManager.RemoveCache(r_path)
     except errors.BlockDeviceError, err:
       msgs.append(str(err))
-      result = False
 
   if disk.children:
     for child in disk.children:
-      c_status, c_msg = BlockdevShutdown(child)
-      result = result and c_status
-      if c_msg: # not an empty message
-        msgs.append(c_msg)
+      try:
+        BlockdevShutdown(child)
+      except RPCFail, err:
+        msgs.append(str(err))
 
-  if not result:
+  if msgs:
     _Fail("; ".join(msgs))
-  return (True, None)
 
 
 def BlockdevAddchildren(parent_cdev, new_cdevs):
@@ -1322,8 +1340,7 @@ def BlockdevAddchildren(parent_cdev, new_cdevs):
   @param parent_cdev: the disk to which we should add children
   @type new_cdevs: list of L{objects.Disk}
   @param new_cdevs: the list of children which we should add
-  @rtype: boolean
-  @return: the success of the operation
+  @rtype: None
 
   """
   parent_bdev = _RecursiveFindBD(parent_cdev)
@@ -1333,7 +1350,6 @@ def BlockdevAddchildren(parent_cdev, new_cdevs):
   if new_bdevs.count(None) > 0:
     _Fail("Can't find new device(s) to add: %s:%s", new_bdevs, new_cdevs)
   parent_bdev.AddChildren(new_bdevs)
-  return (True, None)
 
 
 def BlockdevRemovechildren(parent_cdev, new_cdevs):
@@ -1343,8 +1359,7 @@ def BlockdevRemovechildren(parent_cdev, new_cdevs):
   @param parent_cdev: the disk from which we should remove children
   @type new_cdevs: list of L{objects.Disk}
   @param new_cdevs: the list of children which we should remove
-  @rtype: boolean
-  @return: the success of the operation
+  @rtype: None
 
   """
   parent_bdev = _RecursiveFindBD(parent_cdev)
@@ -1362,7 +1377,6 @@ def BlockdevRemovechildren(parent_cdev, new_cdevs):
     else:
       devs.append(rpath)
   parent_bdev.RemoveChildren(devs)
-  return (True, None)
 
 
 def BlockdevGetmirrorstatus(disks):
@@ -1383,14 +1397,16 @@ def BlockdevGetmirrorstatus(disks):
     rbd = _RecursiveFindBD(dsk)
     if rbd is None:
       _Fail("Can't find device %s", dsk)
+
     stats.append(rbd.CombinedSyncStatus())
-  return True, stats
+
+  return stats
 
 
 def _RecursiveFindBD(disk):
   """Check if a device is activated.
 
-  If so, return informations about the real device.
+  If so, return information about the real device.
 
   @type disk: L{objects.Disk}
   @param disk: the disk object we need to find
@@ -1404,29 +1420,104 @@ def _RecursiveFindBD(disk):
     for chdisk in disk.children:
       children.append(_RecursiveFindBD(chdisk))
 
-  return bdev.FindDevice(disk.dev_type, disk.physical_id, children)
+  return bdev.FindDevice(disk.dev_type, disk.physical_id, children, disk.size)
 
 
 def BlockdevFind(disk):
   """Check if a device is activated.
 
-  If it is, return informations about the real device.
+  If it is, return information about the real device.
 
   @type disk: L{objects.Disk}
   @param disk: the disk to find
-  @rtype: None or tuple
-  @return: None if the disk cannot be found, otherwise a
-      tuple (device_path, major, minor, sync_percent,
-      estimated_time, is_degraded)
+  @rtype: None or objects.BlockDevStatus
+  @return: None if the disk cannot be found, otherwise a the current
+           information
 
   """
   try:
     rbd = _RecursiveFindBD(disk)
   except errors.BlockDeviceError, err:
     _Fail("Failed to find device: %s", err, exc=True)
+
   if rbd is None:
-    return (True, None)
-  return (True, (rbd.dev_path, rbd.major, rbd.minor) + rbd.GetSyncStatus())
+    return None
+
+  return rbd.GetSyncStatus()
+
+
+def BlockdevGetsize(disks):
+  """Computes the size of the given disks.
+
+  If a disk is not found, returns None instead.
+
+  @type disks: list of L{objects.Disk}
+  @param disks: the list of disk to compute the size for
+  @rtype: list
+  @return: list with elements None if the disk cannot be found,
+      otherwise the size
+
+  """
+  result = []
+  for cf in disks:
+    try:
+      rbd = _RecursiveFindBD(cf)
+    except errors.BlockDeviceError, err:
+      result.append(None)
+      continue
+    if rbd is None:
+      result.append(None)
+    else:
+      result.append(rbd.GetActualSize())
+  return result
+
+
+def BlockdevExport(disk, dest_node, dest_path, cluster_name):
+  """Export a block device to a remote node.
+
+  @type disk: L{objects.Disk}
+  @param disk: the description of the disk to export
+  @type dest_node: str
+  @param dest_node: the destination node to export to
+  @type dest_path: str
+  @param dest_path: the destination path on the target node
+  @type cluster_name: str
+  @param cluster_name: the cluster name, needed for SSH hostalias
+  @rtype: None
+
+  """
+  real_disk = _RecursiveFindBD(disk)
+  if real_disk is None:
+    _Fail("Block device '%s' is not set up", disk)
+
+  real_disk.Open()
+
+  # the block size on the read dd is 1MiB to match our units
+  expcmd = utils.BuildShellCmd("set -e; set -o pipefail; "
+                               "dd if=%s bs=1048576 count=%s",
+                               real_disk.dev_path, str(disk.size))
+
+  # we set here a smaller block size as, due to ssh buffering, more
+  # than 64-128k will mostly ignored; we use nocreat to fail if the
+  # device is not already there or we pass a wrong path; we use
+  # notrunc to no attempt truncate on an LV device; we use oflag=dsync
+  # to not buffer too much memory; this means that at best, we flush
+  # every 64k, which will not be very fast
+  destcmd = utils.BuildShellCmd("dd of=%s conv=nocreat,notrunc bs=65536"
+                                " oflag=dsync", dest_path)
+
+  remotecmd = _GetSshRunner(cluster_name).BuildCmd(dest_node,
+                                                   constants.GANETI_RUNAS,
+                                                   destcmd)
+
+  # all commands have been checked, so we're safe to combine them
+  command = '|'.join([expcmd, utils.ShellQuoteArgs(remotecmd)])
+
+  result = utils.RunCmd(["bash", "-c", command])
+
+  if result.failed:
+    _Fail("Disk copy command '%s' returned error: %s"
+          " output: %s", command, result.fail_reason, result.output)
 
 
 def UploadFile(file_name, data, mode, uid, gid, atime, mtime):
@@ -1449,28 +1540,13 @@ def UploadFile(file_name, data, mode, uid, gid, atime, mtime):
   @param atime: the atime to set on the file (can be None)
   @type mtime: float
   @param mtime: the mtime to set on the file (can be None)
-  @rtype: boolean
-  @return: the success of the operation; errors are logged
-      in the node daemon log
+  @rtype: None
 
   """
   if not os.path.isabs(file_name):
     _Fail("Filename passed to UploadFile is not absolute: '%s'", file_name)
 
-  allowed_files = set([
-    constants.CLUSTER_CONF_FILE,
-    constants.ETC_HOSTS,
-    constants.SSH_KNOWN_HOSTS_FILE,
-    constants.VNC_PASSWORD_FILE,
-    constants.RAPI_CERT_FILE,
-    constants.RAPI_USERS_FILE,
-    ])
-
-  for hv_name in constants.HYPER_TYPES:
-    hv_class = hypervisor.GetHypervisor(hv_name)
-    allowed_files.update(hv_class.GetAncillaryFiles())
-
-  if file_name not in allowed_files:
+  if file_name not in _ALLOWED_UPLOAD_FILES:
     _Fail("Filename passed to UploadFile not in allowed upload targets: '%s'",
           file_name)
 
@@ -1478,7 +1554,6 @@ def UploadFile(file_name, data, mode, uid, gid, atime, mtime):
 
   utils.WriteFile(file_name, data=raw_data, mode=mode, uid=uid, gid=gid,
                   atime=atime, mtime=mtime)
-  return (True, "success")
 
 
 def WriteSsconfFiles(values):
@@ -1488,7 +1563,6 @@ def WriteSsconfFiles(values):
 
   """
   ssconf.SimpleStore().WriteFiles(values)
-  return True, None
 
 
 def _ErrnoOrStr(err):
@@ -1509,7 +1583,7 @@ def _ErrnoOrStr(err):
   return detail
 
 
-def _OSOndiskVersion(name, os_dir):
+def _OSOndiskAPIVersion(name, os_dir):
   """Compute and return the API version of a given OS.
 
   This function will try to read the API version of the OS given by
@@ -1524,31 +1598,26 @@ def _OSOndiskVersion(name, os_dir):
       data holding either the vaid versions or an error message
 
   """
-  api_file = os.path.sep.join([os_dir, "ganeti_api_version"])
+  api_file = os.path.sep.join([os_dir, constants.OS_API_FILE])
 
   try:
     st = os.stat(api_file)
   except EnvironmentError, err:
-    return False, ("Required file 'ganeti_api_version' file not"
-                   " found under path %s: %s" % (os_dir, _ErrnoOrStr(err)))
+    return False, ("Required file '%s' not found under path %s: %s" %
+                   (constants.OS_API_FILE, os_dir, _ErrnoOrStr(err)))
 
   if not stat.S_ISREG(stat.S_IFMT(st.st_mode)):
-    return False, ("File 'ganeti_api_version' file at %s is not"
-                   " a regular file" % os_dir)
+    return False, ("File '%s' in %s is not a regular file" %
+                   (constants.OS_API_FILE, os_dir))
 
   try:
-    f = open(api_file)
-    try:
-      api_versions = f.readlines()
-    finally:
-      f.close()
+    api_versions = utils.ReadFile(api_file).splitlines()
   except EnvironmentError, err:
     return False, ("Error while reading the API version file at %s: %s" %
                    (api_file, _ErrnoOrStr(err)))
 
-  api_versions = [version.strip() for version in api_versions]
   try:
-    api_versions = [int(version) for version in api_versions]
+    api_versions = [int(version.strip()) for version in api_versions]
   except (TypeError, ValueError), err:
     return False, ("API version(s) can't be converted to integer: %s" %
                    str(err))
@@ -1581,7 +1650,7 @@ def DiagnoseOS(top_dirs=None):
       try:
         f_names = utils.ListVisibleFiles(dir_name)
       except EnvironmentError, err:
-        logging.exception("Can't list the OS directory %s", dir_name)
+        logging.exception("Can't list the OS directory %s: %s", dir_name, err)
         break
       for name in f_names:
         os_path = os.path.sep.join([dir_name, name])
@@ -1592,7 +1661,7 @@ def DiagnoseOS(top_dirs=None):
           diagnose = os_inst
         result.append((name, os_path, status, diagnose))
 
-  return True, result
+  return result
 
 
 def _TryOSFromDisk(name, base_dir=None):
@@ -1616,14 +1685,14 @@ def _TryOSFromDisk(name, base_dir=None):
   else:
     os_dir = os.path.sep.join([base_dir, name])
 
-  status, api_versions = _OSOndiskVersion(name, os_dir)
+  status, api_versions = _OSOndiskAPIVersion(name, os_dir)
   if not status:
     # push the error up
     return status, api_versions
 
-  if constants.OS_API_VERSION not in api_versions:
+  if not constants.OS_API_VERSIONS.intersection(api_versions):
     return False, ("API version mismatch for path '%s': found %s, want %s." %
-                   (os_dir, api_versions, constants.OS_API_VERSION))
+                   (os_dir, api_versions, constants.OS_API_VERSIONS))
 
   # OS Scripts dictionary, we will populate it with the actual script names
   os_scripts = dict.fromkeys(constants.OS_SCRIPTS)
@@ -1680,11 +1749,13 @@ def OSFromDisk(name, base_dir=None):
   return payload
 
 
-def OSEnvironment(instance, debug=0):
+def OSEnvironment(instance, os, debug=0):
   """Calculate the environment for an os script.
 
   @type instance: L{objects.Instance}
   @param instance: target instance for the os script run
+  @type os: L{objects.OS}
+  @param os: operating system for which the environment is being built
   @type debug: integer
   @param debug: debug level (0 or 1, for OS Api 10)
   @rtype: dict
@@ -1694,7 +1765,8 @@ def OSEnvironment(instance, debug=0):
 
   """
   result = {}
-  result['OS_API_VERSION'] = '%d' % constants.OS_API_VERSION
+  api_version = max(constants.OS_API_VERSIONS.intersection(os.api_versions))
+  result['OS_API_VERSION'] = '%d' % api_version
   result['INSTANCE_NAME'] = instance.name
   result['INSTANCE_OS'] = instance.os
   result['HYPERVISOR'] = instance.hypervisor
@@ -1730,6 +1802,10 @@ def OSEnvironment(instance, debug=0):
       result['NIC_%d_FRONTEND_TYPE' % idx] = \
         instance.hvparams[constants.HV_NIC_TYPE]
 
+  for source, kind in [(instance.beparams, "BE"), (instance.hvparams, "HV")]:
+    for key, value in source.items():
+      result["INSTANCE_%s_%s" % (kind, key)] = str(value)
+
   return result
 
 def BlockdevGrow(disk, amount):
@@ -1755,8 +1831,6 @@ def BlockdevGrow(disk, amount):
   except errors.BlockDeviceError, err:
     _Fail("Failed to grow block device: %s", err, exc=True)
 
-  return True, None
-
 
 def BlockdevSnapshot(disk):
   """Create a snapshot copy of a block device.
@@ -1784,7 +1858,7 @@ def BlockdevSnapshot(disk):
     r_dev = _RecursiveFindBD(disk)
     if r_dev is not None:
       # let's stay on the safe side and ask for the full size, for now
-      return True, r_dev.Snapshot(disk.size)
+      return r_dev.Snapshot(disk.size)
     else:
       _Fail("Cannot find block device %s", disk)
   else:
@@ -1806,13 +1880,12 @@ def ExportSnapshot(disk, dest_node, instance, cluster_name, idx):
   @type idx: int
   @param idx: the index of the disk in the instance's disk list,
       used to export to the OS scripts environment
-  @rtype: boolean
-  @return: the success of the operation
+  @rtype: None
 
   """
-  export_env = OSEnvironment(instance)
-
   inst_os = OSFromDisk(instance.os)
+  export_env = OSEnvironment(instance, inst_os)
+
   export_script = inst_os.export_script
 
   logfile = "%s/exp-%s-%s-%s.log" % (constants.LOG_OS_DIR, inst_os.name,
@@ -1834,8 +1907,8 @@ def ExportSnapshot(disk, dest_node, instance, cluster_name, idx):
   # the target command is built out of three individual commands,
   # which are joined by pipes; we check each individual command for
   # valid parameters
-  expcmd = utils.BuildShellCmd("cd %s; %s 2>%s", inst_os.path,
-                               export_script, logfile)
+  expcmd = utils.BuildShellCmd("set -e; set -o pipefail; cd %s; %s 2>%s",
+                               inst_os.path, export_script, logfile)
 
   comprcmd = "gzip"
 
@@ -1848,14 +1921,12 @@ def ExportSnapshot(disk, dest_node, instance, cluster_name, idx):
   # all commands have been checked, so we're safe to combine them
   command = '|'.join([expcmd, comprcmd, utils.ShellQuoteArgs(remotecmd)])
 
-  result = utils.RunCmd(command, env=export_env)
+  result = utils.RunCmd(["bash", "-c", command], env=export_env)
 
   if result.failed:
     _Fail("OS snapshot export command '%s' returned error: %s"
           " output: %s", command, result.fail_reason, result.output)
 
-  return (True, None)
-
 
 def FinalizeExport(instance, snap_disks):
   """Write out the export configuration information.
@@ -1867,8 +1938,7 @@ def FinalizeExport(instance, snap_disks):
   @param snap_disks: list of snapshot block devices, which
       will be used to get the actual name of the dump file
 
-  @rtype: boolean
-  @return: the success of the operation
+  @rtype: None
 
   """
   destdir = os.path.join(constants.EXPORT_DIR, instance.name + ".new")
@@ -1920,8 +1990,6 @@ def FinalizeExport(instance, snap_disks):
   shutil.rmtree(finaldestdir, True)
   shutil.move(destdir, finaldestdir)
 
-  return True, None
-
 
 def ExportInfo(dest):
   """Get export configuration information.
@@ -1943,7 +2011,7 @@ def ExportInfo(dest):
       not config.has_section(constants.INISECT_INS)):
     _Fail("Export info file doesn't have the required fields")
 
-  return True, config.Dumps()
+  return config.Dumps()
 
 
 def ImportOSIntoInstance(instance, src_node, src_images, cluster_name):
@@ -1959,8 +2027,8 @@ def ImportOSIntoInstance(instance, src_node, src_images, cluster_name):
   @return: each boolean represent the success of importing the n-th disk
 
   """
-  import_env = OSEnvironment(instance)
   inst_os = OSFromDisk(instance.os)
+  import_env = OSEnvironment(instance, inst_os)
   import_script = inst_os.import_script
 
   logfile = "%s/import-%s-%s-%s.log" % (constants.LOG_OS_DIR, instance.os,
@@ -1992,7 +2060,6 @@ def ImportOSIntoInstance(instance, src_node, src_images, cluster_name):
 
   if final_result:
     _Fail("; ".join(final_result), log=False)
-  return True, None
 
 
 def ListExports():
@@ -2003,7 +2070,7 @@ def ListExports():
 
   """
   if os.path.isdir(constants.EXPORT_DIR):
-    return True, utils.ListVisibleFiles(constants.EXPORT_DIR)
+    return utils.ListVisibleFiles(constants.EXPORT_DIR)
   else:
     _Fail("No exports directory")
 
@@ -2013,8 +2080,7 @@ def RemoveExport(export):
 
   @type export: str
   @param export: the name of the export to remove
-  @rtype: boolean
-  @return: the success of the operation
+  @rtype: None
 
   """
   target = os.path.join(constants.EXPORT_DIR, export)
@@ -2024,8 +2090,6 @@ def RemoveExport(export):
   except EnvironmentError, err:
     _Fail("Error while removing the export: %s", err, exc=True)
 
-  return True, None
-
 
 def BlockdevRename(devlist):
   """Rename a list of block devices.
@@ -2066,7 +2130,6 @@ def BlockdevRename(devlist):
       result = False
   if not result:
     _Fail("; ".join(msgs))
-  return True, None
 
 
 def _TransformFileStorageDir(file_storage_dir):
@@ -2114,7 +2177,6 @@ def CreateFileStorageDir(file_storage_dir):
     except OSError, err:
       _Fail("Cannot create file storage directory '%s': %s",
             file_storage_dir, err, exc=True)
-  return True, None
 
 
 def RemoveFileStorageDir(file_storage_dir):
@@ -2126,7 +2188,7 @@ def RemoveFileStorageDir(file_storage_dir):
   @param file_storage_dir: the directory we should cleanup
   @rtype: tuple (success,)
   @return: tuple of one element, C{success}, denoting
-      whether the operation was successfull
+      whether the operation was successful
 
   """
   file_storage_dir = _TransformFileStorageDir(file_storage_dir)
@@ -2141,8 +2203,6 @@ def RemoveFileStorageDir(file_storage_dir):
       _Fail("Cannot remove file storage directory '%s': %s",
             file_storage_dir, err)
 
-  return True, None
-
 
 def RenameFileStorageDir(old_file_storage_dir, new_file_storage_dir):
   """Rename the file storage directory.
@@ -2172,7 +2232,6 @@ def RenameFileStorageDir(old_file_storage_dir, new_file_storage_dir):
     if os.path.exists(old_file_storage_dir):
       _Fail("Cannot rename '%s' to '%s': both locations exist",
             old_file_storage_dir, new_file_storage_dir)
-  return True, None
 
 
 def _EnsureJobQueueFile(file_name):
@@ -2211,8 +2270,6 @@ def JobQueueUpdate(file_name, content):
   # Write and replace the file atomically
   utils.WriteFile(file_name, data=_Decompress(content))
 
-  return True, None
-
 
 def JobQueueRename(old, new):
   """Renames a job queue file.
@@ -2232,8 +2289,6 @@ def JobQueueRename(old, new):
 
   utils.RenameFile(old, new, mkdir=True)
 
-  return True, None
-
 
 def JobQueueSetDrainFlag(drain_flag):
   """Set the drain flag for the queue.
@@ -2252,8 +2307,6 @@ def JobQueueSetDrainFlag(drain_flag):
   else:
     utils.RemoveFile(constants.JOB_QUEUE_DRAIN_FILE)
 
-  return True, None
-
 
 def BlockdevClose(instance_name, disks):
   """Closes the given block devices.
@@ -2290,7 +2343,6 @@ def BlockdevClose(instance_name, disks):
   else:
     if instance_name:
       _RemoveBlockDevLinks(instance_name, disks)
-    return (True, "All devices secondary")
 
 
 def ValidateHVParams(hvname, hvparams):
@@ -2300,17 +2352,12 @@ def ValidateHVParams(hvname, hvparams):
   @param hvname: the hypervisor name
   @type hvparams: dict
   @param hvparams: the hypervisor parameters to be validated
-  @rtype: tuple (success, message)
-  @return: a tuple of success and message, where success
-      indicates the succes of the operation, and message
-      which will contain the error details in case we
-      failed
+  @rtype: None
 
   """
   try:
     hv_type = hypervisor.GetHypervisor(hvname)
     hv_type.ValidateParameters(hvparams)
-    return (True, "Validation passed")
   except errors.HypervisorError, err:
     _Fail(str(err), log=False)
 
@@ -2323,16 +2370,16 @@ def DemoteFromMC():
   master, myself = ssconf.GetMasterAndMyself()
   if master == myself:
     _Fail("ssconf status shows I'm the master node, will not demote")
-  pid_file = utils.DaemonPidFileName(constants.MASTERD_PID)
+  pid_file = utils.DaemonPidFileName(constants.MASTERD)
   if utils.IsProcessAlive(utils.ReadPidFile(pid_file)):
     _Fail("The master daemon is running, will not demote")
   try:
-    utils.CreateBackup(constants.CLUSTER_CONF_FILE)
+    if os.path.isfile(constants.CLUSTER_CONF_FILE):
+      utils.CreateBackup(constants.CLUSTER_CONF_FILE)
   except EnvironmentError, err:
     if err.errno != errno.ENOENT:
       _Fail("Error while backing up cluster file: %s", err, exc=True)
   utils.RemoveFile(constants.CLUSTER_CONF_FILE)
-  return (True, "Done")
 
 
 def _FindDisks(nodes_ip, disks):
@@ -2367,7 +2414,6 @@ def DrbdDisconnectNet(nodes_ip, disks):
     except errors.BlockDeviceError, err:
       _Fail("Can't change network configuration to standalone mode: %s",
             err, exc=True)
-  return (True, "All disks are now disconnected")
 
 
 def DrbdAttachNet(nodes_ip, disks, instance_name, multimaster):
@@ -2408,7 +2454,7 @@ def DrbdAttachNet(nodes_ip, disks, instance_name, multimaster):
         # standalone, even though this should not happen with the
         # new staged way of changing disk configs
         try:
-          rd.ReAttachNet(multimaster)
+          rd.AttachNet(multimaster)
         except errors.BlockDeviceError, err:
           _Fail("Can't change network configuration: %s", err)
     if all_connected:
@@ -2424,11 +2470,6 @@ def DrbdAttachNet(nodes_ip, disks, instance_name, multimaster):
         rd.Open()
       except errors.BlockDeviceError, err:
         _Fail("Can't change to primary mode: %s", err)
-  if multimaster:
-    msg = "multi-master and primary"
-  else:
-    msg = "single-master"
-  return (True, "Disks are now configured as %s" % msg)
 
 
 def DrbdWaitSync(nodes_ip, disks):
@@ -2439,7 +2480,6 @@ def DrbdWaitSync(nodes_ip, disks):
 
   min_resync = 100
   alldone = True
-  failure = False
   for rd in bdevs:
     stats = rd.GetProcStatus()
     if not (stats.is_connected or stats.is_in_resync):
@@ -2448,7 +2488,7 @@ def DrbdWaitSync(nodes_ip, disks):
     if stats.sync_percent is not None:
       min_resync = min(min_resync, stats.sync_percent)
 
-  return (True, (alldone, min_resync))
+  return (alldone, min_resync)
 
 
 def PowercycleNode(hypervisor_type):
@@ -2461,11 +2501,11 @@ def PowercycleNode(hypervisor_type):
   hyper = hypervisor.GetHypervisor(hypervisor_type)
   try:
     pid = os.fork()
-  except OSError, err:
+  except OSError:
     # if we can't fork, we'll pretend that we're in the child process
     pid = 0
   if pid > 0:
-    return (True, "Reboot scheduled in 5 seconds")
+    return "Reboot scheduled in 5 seconds"
   time.sleep(5)
   hyper.PowercycleNode()
 
@@ -2576,9 +2616,9 @@ class HooksRunner(object):
     dir_name = "%s/%s" % (self._BASE_DIR, subdir)
     try:
       dir_contents = utils.ListVisibleFiles(dir_name)
-    except OSError, err:
+    except OSError:
       # FIXME: must log output in case of failures
-      return True, rr
+      return rr
 
     # we use the standard python sort order,
     # so 00name is the recommended naming scheme
@@ -2597,7 +2637,7 @@ class HooksRunner(object):
           rrval = constants.HKR_SUCCESS
       rr.append(("%s/%s" % (subdir, relname), rrval, output))
 
-    return True, rr
+    return rr
 
 
 class IAllocatorRunner(object):
@@ -2637,7 +2677,7 @@ class IAllocatorRunner(object):
     finally:
       os.unlink(fin_name)
 
-    return True, result.stdout
+    return result.stdout
 
 
 class DevCacheManager(object):
@@ -2698,7 +2738,7 @@ class DevCacheManager(object):
     try:
       utils.WriteFile(fpath, data=fdata)
     except EnvironmentError, err:
-      logging.exception("Can't update bdev cache for %s", dev_path)
+      logging.exception("Can't update bdev cache for %s: %s", dev_path, err)
 
   @classmethod
   def RemoveCache(cls, dev_path):
@@ -2720,4 +2760,4 @@ class DevCacheManager(object):
     try:
       utils.RemoveFile(fpath)
     except EnvironmentError, err:
-      logging.exception("Can't update bdev cache for %s", dev_path)
+      logging.exception("Can't update bdev cache for %s: %s", dev_path, err)