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I didn't mean to imply that post-copy always results in data loss.
But this is possible if the network connection between source and
destination host is disconnected during the post-copy operation.

Am Mo., 18. Sept. 2023 um 12:14 Uhr schrieb Michel Jouvin
<michel.jouvin at ijclab.in2p3.fr>:
>
> Hi,
>
> post-copy looks to meas a very attractive approach for these
> heavy-loaded VMs but I didn't understand that there is an inherent risk
> of data-loss (except if there is an implementation bug)... Are you sure?
>
> Michel
>
> Le 18/09/2023 à 11:29, Rafa a écrit :
> > As I can read and understand from the source compute logs,
> > the memory is copied over successfully and there is no migration timeout.
> > But after the instance is paused there is something wrong happening.
> > I first thought it could be the short migration downtime (default=500ms),
> > that's why I increased the "live_migration_downtime" to higher values
> > (max was 300000ms; just for testing:) ) and nothing changed.
> >
> > And the error message doesn't say much either.
> >
> > I don't really want to use post-copy as it can lead to data loss.
> >
> > Auto Converge doesn't seem to help either.
> >
> >
> >
> > Am Fr., 15. Sept. 2023 um 13:56 Uhr schrieb <smooney at redhat.com>:
> >> On Thu, 2023-09-14 at 19:07 +0200, Rafa wrote:
> >>>> Hi, could you share logs from the target compute node as well?
> >>> yes, here: https://paste.openstack.org/show/blpJE8krA1N6PVaLTVF0/
> >>>
> >> if the vm is under heavy memory load then its advisable ot use post-copy live migration.
> >>
> >> in general live migration is not intened to be used with a vm under load
> >> as there is no gurenettee that it will ever complete. post-copy live migration
> >> can signifcantly increae the probablity that a vm under load will live migrate
> >> in a reasonabel amount of time.
> >>
> >> https://docs.openstack.org/nova/latest/configuration/config.html#libvirt.live_migration_permit_post_copy
> >>
> >> auto converge can also help but tis less important
> >>
> >> https://docs.openstack.org/nova/latest/configuration/config.html#libvirt.live_migration_permit_auto_converge
> >>
>