[PATCH v1 25/25] docs/kbase: introduce migrationinternals.rst
Michal Privoznik
mprivozn at redhat.com
Mon Jul 13 14:32:41 UTC 2020
On 7/13/20 3:42 PM, Daniel Henrique Barboza wrote:
>
>
> On 7/13/20 10:20 AM, Michal Privoznik wrote:
>> On 7/13/20 11:49 AM, Daniel Henrique Barboza wrote:
>>> This document describes briefly how Libvirt migration internals
>>> works, complementing the info available in migration.html.in.
>>>
>>> Signed-off-by: Daniel Henrique Barboza <danielhb413 at gmail.com>
>>> ---
>>> docs/kbase/migrationinternals.rst | 174 ++++++++++++++++++++++++++++++
>>> 1 file changed, 174 insertions(+)
>>> create mode 100644 docs/kbase/migrationinternals.rst
>>>
>>> diff --git a/docs/kbase/migrationinternals.rst
>>> b/docs/kbase/migrationinternals.rst
>>> new file mode 100644
>>> index 0000000000..869ee99bd7
>>> --- /dev/null
>>> +++ b/docs/kbase/migrationinternals.rst
>>> @@ -0,0 +1,174 @@
>>> +===========================
>>> +Libvirt migration internals
>>> +===========================
>>> +
>>> +.. contents::
>>> +
>>> +Migration is a multi-step operation with at least two distinct actors,
>>> +the source and the destination libvirtd daemons, and a lot of failure
>>> +points. This document describes the basic migration workflow in the
>>> +code level, as a way to complement `the base migration docs
>>> <migration.html>`_
>>> +and help developers to get up to speed quicker with the code.
>>> +
>>> +In this document, unless stated otherwise, these conventions are
>>> followed:
>>> +
>>> +* 'user' refers to any entity that initiates a migration, regardless
>>> of being
>>> + an human using 'virsh' or a program consuming the Libvirt API;
>>> +
>>> +* 'source' refers to the source host of the migration, where the
>>> guest currently
>>> + exists;
>>> +
>>> +* 'destination' refers to the destination host of the migration. As of
>>> + Libvirt 6.5.0 local migration isn't supported, thus source and
>>> destination
>>> + refers to different hosts;
>>
>> Is this right? What commit is reponsible for this change?
>
>
> I guess my wording here is unclear. What I wanted to say is that, at
> least up to the
> current release we're at now (6.5.0), localhost migration (i.e. source
> and destination
> is the same host) isn't supported. I wanted to mention it this way
> because there's always
> the chance that Libvirt comes around and implements it.
>
>
>
> If you want a commit id, the error message warning about localhost
> migration appeared
> first here:
>
>
> commit 8654175c5b0c3db9e5f70907f102f0f900355d28
> Author: Daniel P. Berrange <berrange at redhat.com>
> Date: Mon Jan 24 18:06:16 2011 +0000
Yeah, I was more interested whether we merged recently a patch that
explicitly forbids same host migration. Speaking of which, to some
extent we support same host migration (see v6.2.0-rc1~282) if both
libvirts live in separate containers (and effectively think they run on
different hosts).
Can you post a diff that I can squash in before merging?
Michal
More information about the libvir-list
mailing list