[pve-devel] [PATCH v3 qemu-server 09/10] migrate: add remote migration handling

[Fabian Grünbichler]

On January 11, 2022 9:19 am, Thomas Lamprecht wrote:
> On 04.01.22 17:44, Roland wrote:
>>>>   +sub phase2_start_remote_cluster {
>>>> +    my ($self, $vmid, $params) = @_;
>>>> +
>>>> +    die "insecure migration to remote cluster not implemented\n"
>>>> +    if $params->{migrate_opts}->{type} ne 'websocket';
>>>> +
>>>> +    my $remote_vmid = $self->{opts}->{remote}->{vmid};
>>>> +
>>>> +    my $res = PVE::Tunnel::write_tunnel($self->{tunnel}, 10,
>>>> "start", $params);
>>>
>>> 10 seconds feels a bit short to me.
> 
> @Fabian(s):
> 
> Why not use the same as vm_start_nolock + some buffer? E.g.,
> 
> ($params->{timeout} // config_aware_timeout($conf, $resume)) + 10;
> 
> That should be quite generous, as the worst case time for the start for
> incoming migration, which is always paused so not doing much, is normally
> way lower than a cold-start.
> 
> I mean, we're in an worker task and do not really care much if setup needs
> a bit longer.

yeah, that sounds like a good idea :) also gives us future updates / 
special case handling for setups that take longer 'for free', including 
things like a possible manual override via the guest config.