The documentation explains how LUMoveInstance, LUInstanceFailover, and LUInstanceMigrate are related.
Signed-off-by: Aaron Karper <[email protected]> --- lib/cmdlib/instance.py | 11 +++++++++++ lib/cmdlib/instance_migration.py | 17 +++++++++++++++-- 2 files changed, 26 insertions(+), 2 deletions(-) diff --git a/lib/cmdlib/instance.py b/lib/cmdlib/instance.py index 9659ca7..41642ab 100644 --- a/lib/cmdlib/instance.py +++ b/lib/cmdlib/instance.py @@ -2055,6 +2055,17 @@ class LUInstanceRemove(LogicalUnit): class LUInstanceMove(LogicalUnit): """Move an instance by data-copying. + This LU is only used if the instance needs to be moved by copying the data + from one node in the cluster to another. The instance is shut down and + the data is copied to the new node and the configuration change is propagated, + then the instance is started again. + + See also: + L{LUInstanceFailover} for moving an instance on shared storage (no copying + required). + + L{LUInstanceMigrate} for the live migration of an instance (no shutdown + required). """ HPATH = "instance-move" HTYPE = constants.HTYPE_INSTANCE diff --git a/lib/cmdlib/instance_migration.py b/lib/cmdlib/instance_migration.py index 56a6f53..b4435e7 100644 --- a/lib/cmdlib/instance_migration.py +++ b/lib/cmdlib/instance_migration.py @@ -114,6 +114,14 @@ def _DeclareLocksForMigration(lu, level): class LUInstanceFailover(LogicalUnit): """Failover an instance. + This is migration by shutting the instance down, but with the disks + of the instance already available on the new node. + + See also: + L{LUInstanceMove} for moving an instance by copying the data. + + L{LUInstanceMigrate} for the live migration of an instance (no shutdown + required). """ HPATH = "instance-failover" HTYPE = constants.HTYPE_INSTANCE @@ -183,9 +191,14 @@ class LUInstanceFailover(LogicalUnit): class LUInstanceMigrate(LogicalUnit): """Migrate an instance. - This is migration without shutting down, compared to the failover, - which is done with shutdown. + This is migration without shutting down (live migration) and the disks are + already available on the new node. + + See also: + L{LUInstanceMove} for moving an instance by copying the data. + L{LUInstanceFailover} for the migration of an instance where a shutdown is + required. """ HPATH = "instance-migrate" HTYPE = constants.HTYPE_INSTANCE -- 2.1.0.rc2.206.gedb03e5
