Thanks. yeah I am not sure if I want to use the post-copy feature. A
few packets timeout is acceptable I think.

Could we say that with 'live_migration_permit_auto_converge=true'
enabled for nova.conf, it might ONLY cause instance slow-down during
its live migration process, ONLY when it detects that the instance's
memory writes are too fast to keep up with?

This means it won't cause instance slow-down when there's no live
migration going on?

Hai

On Tue, Oct 17, 2023 at 2:43 AM Nguyễn Hữu Khôi
<nguyenhuukhoinw@gmail.com> wrote:
>
>
> Auto-converge will  slows down instance CPU until the memory copy process is faster than the instance's memory writes so i test on my system and the instance can be timeout some packets before it was migrated completely,
>
> Enable post-copy, I use in my system because I see that instance won't be timeout when it was live migrated but:
>
> Possible downsides:
>
> When the network connection between source and destination is interrupted, page faults cannot be resolved anymore, and the virtual machine is rebooted.
> Post-copy may lead to an increased page fault rate during migration, which can slow the instance down
>
> In my case, I don't see  impacts with this option till now.
>
>
> https://docs.openstack.org/nova/yoga/admin/live-migration-usage.html
>
>
> Nguyen Huu Khoi
>
>
> On Tue, Oct 17, 2023 at 1:08 PM hai wu <haiwu.us@gmail.com> wrote:
>>
>> Do you enable auto-converge for nova instance live migration on all
>> production hypervisor hosts?