07c7e5caf2
Currently live migration runs with the default maximum downtime setting defined by QEMU. This is often inadequate to allow migration of large VMs to ever complete. Rather than trying to invent a new policy for changing downtime in OpenStack, copy the existing logic that is successfully battle tested by the oVirt project in VDSM. Note that setting the downtime step delay based on guest RAM size is an inexact science, as RAM size is only one factor influencing success of migration. Just as important is the rate of dirtying data in the guest, but this is based on guest workload which is not something Nova has visibility into. The bottleneck is the network which needs to be able to keep up with the dirtying of data in the guest. The greater the overall RAM size, the more time is required to transfer the total guest memory. So for larger guest sizes, we need to allow greater time for the guest to attempt to successfully migrate before increasing the max downtime. Scaling downtime step delay according to the overall guest RAM size is a reasonable, albeit not foolproof, way to tune migration to increase chances of success. This adds three host level config parameters which admins can use to control the base downtime value and the rate at which downtime is allowed to be increased during migration. Related-bug: #1429220 DocImpact: three new libvirt configuration parameters in nova.conf allow the administrator to control the maximum permitted downtime for migration making migration more likely to complete for large VMs. Change-Id: I1992ffe9d3b2ff8d436cf1c419af9a238a8fecd8 |
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|---|---|---|
| contrib | ||
| devstack | ||
| doc | ||
| etc/nova | ||
| nova | ||
| plugins/xenserver | ||
| tools | ||
| .coveragerc | ||
| .gitignore | ||
| .gitreview | ||
| .mailmap | ||
| .testr.conf | ||
| CONTRIBUTING.rst | ||
| HACKING.rst | ||
| LICENSE | ||
| MAINTAINERS | ||
| MANIFEST.in | ||
| README.rst | ||
| babel.cfg | ||
| bandit.yaml | ||
| openstack-common.conf | ||
| requirements.txt | ||
| run_tests.sh | ||
| setup.cfg | ||
| setup.py | ||
| test-requirements.txt | ||
| tox.ini | ||
README.rst
OpenStack Nova README
OpenStack Nova provides a cloud computing fabric controller, supporting a wide variety of virtualization technologies, including KVM, Xen, LXC, VMware, and more. In addition to its native API, it includes compatibility with the commonly encountered Amazon EC2 and S3 APIs.
OpenStack Nova is distributed under the terms of the Apache License, Version 2.0. The full terms and conditions of this license are detailed in the LICENSE file.
Nova primarily consists of a set of Python daemons, though it requires and integrates with a number of native system components for databases, messaging and virtualization capabilities.
To keep updated with new developments in the OpenStack project follow @openstack on Twitter.
To learn how to deploy OpenStack Nova, consult the documentation available online at:
For information about the different compute (hypervisor) drivers supported by Nova, read this page on the wiki:
In the unfortunate event that bugs are discovered, they should be reported to the appropriate bug tracker. If you obtained the software from a 3rd party operating system vendor, it is often wise to use their own bug tracker for reporting problems. In all other cases use the master OpenStack bug tracker, available at:
Developers wishing to work on the OpenStack Nova project should always base their work on the latest Nova code, available from the master GIT repository at:
Developers should also join the discussion on the mailing list, at:
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
Any new code must follow the development guidelines detailed in the HACKING.rst file, and pass all unit tests. Further developer focused documentation is available at:
For information on how to contribute to Nova, please see the contents of the CONTRIBUTING.rst file.
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