From 395b7a65b6f452d0dc4cbd019ff76c6027544064 Mon Sep 17 00:00:00 2001
From: manasmandlekar <manas.mandlekar@in.ibm.com>
Date: Fri, 18 Nov 2016 07:30:55 -0500
Subject: [PATCH] Allow dynamic enable/disable of SRR capability

Currently to enable or disable the Simplified Remote Restart (SRR)
capability on the VM we need to have the VM in shutoff state. We should
be able to toggle this field dynamically so that the shutdown of a VM is
not needed.

Change-Id: If80660aa72e84e0e65108a36ac47e5bbfaebef80
---
 specs/pike/srr-capability-dynamic-toggle.rst | 145 +++++++++++++++++++
 1 file changed, 145 insertions(+)
 create mode 100644 specs/pike/srr-capability-dynamic-toggle.rst

diff --git a/specs/pike/srr-capability-dynamic-toggle.rst b/specs/pike/srr-capability-dynamic-toggle.rst
new file mode 100644
index 00000000..2deea57a
--- /dev/null
+++ b/specs/pike/srr-capability-dynamic-toggle.rst
@@ -0,0 +1,145 @@
+..
+ This work is licensed under a Creative Commons Attribution 3.0 Unported
+ License.
+
+ http://creativecommons.org/licenses/by/3.0/legalcode
+
+==============================================
+Allow dynamic enable/disable of SRR capability
+==============================================
+
+Include the URL of your launchpad blueprint:
+
+https://blueprints.launchpad.net/nova-powervm/+spec/srr-capability-dynamic-toggle
+
+Currently to enable or disable the SRR capability on the VM we need to have
+the VM in shutoff state. We should be able to toggle this field dynamically
+so that the shutdown of a VM is not needed.
+
+Problem description
+===================
+
+The simplified remote restart (SRR) capability governs whether a VM can be
+rebuilt (remote restarted) on a different host when the host on which the
+VM resides is down. Currently this attribute can be changed only when the VM
+is in shut-off state. This blueprint addresses that by enabling toggle
+of simplified remote restart capability dynamically (while the VM is still
+active).
+
+
+Use Cases
+---------
+
+The end user would like to :
+- Enable the srr capability on the VM without shutting it down so that any
+workloads on the VM are unaffected.
+- Disable the srr capability for a VM which need not be rebuilt to another
+host while the VM is still up and running.
+
+
+Proposed change
+===============
+The SRR capability is a VM level attribute and can be changed using
+the resize operation. In case of a resize operation for an active VM
+- Check if the hypervisor supports dynamic toggle of srr capability.
+- If it is supported proceed with updating of srr capability if it has been
+changed.
+- Throw a warning if update of srr capability is not supported.
+
+
+Alternatives
+------------
+
+None
+
+
+Security impact
+---------------
+
+None
+
+
+End user impact
+---------------
+
+None
+
+
+Performance Impact
+------------------
+
+The change is srr capability is not likely to happen very frequently so this
+should not have a major impact. When the change happens the impact on the
+performance of any other component (the VM, the compute service, the REST
+service, etc.) should be negligible.
+
+
+Deployer impact
+---------------
+
+End user will be able to dynamically the toggle the srr capability for the
+VM. The changes can be utilized immediately once they are deployed.
+
+
+Developer impact
+----------------
+
+None
+
+Implementation
+==============
+
+Assignee(s)
+-----------
+
+
+Primary assignee:
+  manasmandlekar
+
+Other contributors:
+  shyvenug
+
+Work Items
+----------
+NA
+
+Dependencies
+============
+
+Need to work with PowerVM platform team to ensure that the srr toggle
+capability is exposed for the Compute driver to consume.
+
+
+Testing
+=======
+
+The testing of the change requires full Openstack environment with
+Compute resources configured.
+- Ensure srr state for VM can be toggled when it is up and running.
+- Ensure srr state for VM can be toggled when it is shut-off.
+- Perform rebuild operations to ensure that the capability is indeed
+getting utilized.
+
+
+Documentation Impact
+====================
+
+None
+
+
+References
+==========
+
+None
+
+
+History
+=======
+
+.. list-table:: Revisions
+   :header-rows: 1
+
+   * - Release Name
+     - Description
+   * - Pike
+     - Introduced