Re: [PATCH 1/1] NEWS.rst: update with pSeries initial memory fix
On Wed, 2021-01-06 at 12:50 -0300, Daniel Henrique Barboza wrote:
On 1/6/21 12:03 PM, Daniel P. Berrangé wrote:
> virDomainCreateXML on the source Libvirt 7.0.0 on the source will set
> PARSE_ABI_UPDATE and thus set the new smaller RAM size.
>
> Now we live migrate to libvirt 6.9.0 on dest host, and that will not
> set PARSE_ABI_UPDATE and thus set the larger RAM size.
In this scenario, yes, the memory modules on the destination will not be aligned in
PostParse time, but they'll not be used to calculate initialmem/totalmem again
because we don't align memory during live migration.
Since we now perform memory alignment earlier, we will reflect the
aligned size back to the XML instead of re-aligning it at command
line generation time every single time the VM is started.
So the XML that we're going to send to the migration destination will
contain sizes that are already aligned, and thus further alignment
should not be necessary.
At least, that's the theory :)
Daniel, did you test migration between libvirt 7.0.0 and earlier
releases? Can you confirm it works?
--
Andrea Bolognani / Red Hat / Virtualization