Fix disk replace secondary with static minors

The code in 'updating instance configuration' section of the replace
disks with change secondary node was setting a wrong new logical_id for
the drbd devices (only set the new node, not the new minor). The patch
fixes this by remembering the new logical_id that we use for activating
the drbd and reusing it (instead of recomputing).

Since the minors are not needed to be allocated before the LVs are
created, we also move the minor allocation step (currently as None)
after this step.

Reviewed-by: imsnah

diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index 224fc16..7593690 100644 (file)
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -4011,11 +4011,8 @@ class LUReplaceDisks(LogicalUnit):
                                  pri_node)
 
     # Step: create new storage
-
-    minors = [None for dev in instance.disks]
-    logging.debug("Allocated minors %s" % (minors,))
     self.proc.LogStep(3, steps_total, "allocate new storage")
-    for idx, dev in enumerate(instance.disks):
+    for dev in instance.disks:
       size = dev.size
       info("adding new local storage on %s for %s" % (new_node, dev.iv_name))
       # since we *always* want to create this LV, we use the
@@ -4028,20 +4025,22 @@ class LUReplaceDisks(LogicalUnit):
                                    " node '%s'" %
                                    (new_lv.logical_id[1], new_node))
 
-      iv_names[dev.iv_name] = (dev, dev.children, minors[idx])
 
+    # Step 4: dbrd minors and drbd setups changes
+    minors = [None for dev in instance.disks]
+    logging.debug("Allocated minors %s" % (minors,))
     self.proc.LogStep(4, steps_total, "changing drbd configuration")
-    for dev in instance.disks:
+    for dev, new_minor in zip(instance.disks, minors):
       size = dev.size
       info("activating a new drbd on %s for %s" % (new_node, dev.iv_name))
       # create new devices on new_node
-      new_minor = iv_names[dev.iv_name][2]
       if pri_node == dev.logical_id[0]:
         new_logical_id = (pri_node, new_node,
                           dev.logical_id[2], dev.logical_id[3], new_minor)
       else:
         new_logical_id = (new_node, pri_node,
                           dev.logical_id[2], new_minor, dev.logical_id[4])
+      iv_names[dev.iv_name] = (dev, dev.children, new_logical_id)
       new_drbd = objects.Disk(dev_type=constants.LD_DRBD8,
                               logical_id=new_logical_id,
                               children=dev.children)
@@ -4081,8 +4080,8 @@ class LUReplaceDisks(LogicalUnit):
     # if we managed to detach at least one, we update all the disks of
     # the instance to point to the new secondary
     info("updating instance configuration")
-    for dev in instance.disks:
-      dev.logical_id = (pri_node, new_node) + dev.logical_id[2:]
+    for dev, _, new_logical_id in iv_names.itervalues():
+      dev.logical_id = new_logical_id
       cfg.SetDiskID(dev, pri_node)
     cfg.Update(instance)