Add release note for force live migration allocations

When forcing a destination host during live migration, conductor
bypasses the scheduler, performs some pre-migration checks and then
casts to the specified destination compute host directly.

With change I40b5af5e85b1266402a7e4bdeb3705e1b0bd6f3b we are still
bypassing the scheduler but conductor will attempt to allocate
resources against the specified destination host, which could fail
and result in the live migration failing even though the force flag
was specified in the API.

This change simply adds a release note for the new behavior which
was missing from the original fix.

Change-Id: I1811dfa59865c0a878522007e0070f0fde8344f0
Related-Bug: #1712008
This commit is contained in:
Matt Riedemann 2017-09-06 11:13:04 -04:00
parent fa1ac7d965
commit 02a82c41f9
1 changed files with 18 additions and 0 deletions

View File

@ -0,0 +1,18 @@
---
upgrade:
- |
The ``nova-conductor`` service now needs access to the Placement service
in the case of forcing a destination host during a live migration. Ensure
the ``[placement]`` section of nova.conf for the ``nova-conductor`` service
is filled in.
fixes:
- |
When forcing a specified destination host during live migration, the
scheduler is bypassed but resource allocations will still be made in the
Placement service against the forced destination host. If the resource
allocation against the destination host fails, the live migration operation
will fail, regardless of the ``force`` flag being specified in the API.
The guest will be unchanged on the source host. For more details, see
`bug 1712008`_.
.. _bug 1712008: https://bugs.launchpad.net/nova/+bug/1712008