From: Izhar <[email protected]>
---
doc/design-hugepages-ganeti-support.rst | 26 +++++++++++++++++---------
1 file changed, 17 insertions(+), 9 deletions(-)
diff --git a/doc/design-hugepages-ganeti-support.rst
b/doc/design-hugepages-ganeti-support.rst
index a4ba827..ef5ae6e 100644
--- a/doc/design-hugepages-ganeti-support.rst
+++ b/doc/design-hugepages-ganeti-support.rst
@@ -34,21 +34,26 @@ cluster level via the hypervisor parameter ``mem_path`` as::
>--enabled-hypervisors=kvm -nic-parameters link=br100 \
> -H kvm:mem_path=/mount/point/for/hugepages
-This hypervisor parameter is inherited by all the instances as
+This hypervisor parameter is inherited by all the instances as
default although it can be overriden at the instance level.
The following changes will be made to the inheritence behaviour.
-- The hypervisor parameter ``mem_path`` must be made available at the
- node group level (in addition to the cluster level),so that users can
- set it as default for the node group::
+- The hypervisor parameter ``mem_path`` and all other hypervisor
+ parameters will be made available at the node group level (in
+ addition to the cluster level), so that users can set defaults for
+ the node group::
$ gnt-group add/modify\
- > -H kvm:mem_path=/mount/point/for/hugepages
+ > -H hv:parameter=value
+
+ This changes the hypervisor inheritence level as::
+
+ cluster -> group -> OS -> instance
- Furthermore, the hypervisor parameter ``mem_path`` will be changeable
only at the cluster or node group level and users must not be able to
- override this when creating new instances. The following command must
+ override this at OS or instance level. The following command must
produce an error message that ``mem_path`` may only be set at either
the cluster or the node group level::
@@ -66,18 +71,21 @@ the memory reserved for huge pages as:
- mpgsize/hp (Size of a huge page)
mfree and mtotal will be changed to mean "the total and free memory for
-the default method in this cluster/nodegroup"
+the default method in this cluster/nodegroup". Note that the default
+method depends both on the default hypervisor and its parameters.
iAllocator Changes:
-------------------
If huge pages are set as default for a cluster of node group, then
iAllocator must consider the huge pages memory on the nodes, as a
parameter when trying to find the best node for the VM.
+Note that the iallocator will also be changed to use the correct
+parameter depending on the cluster/group.
hbal Changes:
-------------
-The cluster balancer (hbal) will also be changed to consider memory
-pools and recognize memory reserved for huge pages when trying to
+The cluster balancer (hbal) will be changed to use the default memory
+pool and recognize memory reserved for huge pages when trying to
rebalance the cluster.
.. vim: set textwidth=72 :
--
1.8.2.1
