No magic as Ivan said, you may want to check dynamic auto-convergence in case of busy VMs (high RAM change ram i.e. busy MSSQL servers and such) - qemu 2.5 needed for this, can be consumed from 4.11 and onwards - but might not be relevant in your case.
Some very short interruption IS done - i.e. source VM on source host is paused - and last few bits/megabits of RAM are synced to new VM on new host - then source destination VM is killed/destroyed and destination VM (which was paused all time...) will be un-paused/resumed - this should have be less than a second or so... No magic to make it happen without a brief interruption to networking - the faster management network the better (better throughput, so less pause period for VM...) Cheers On Fri, 14 Dec 2018 at 07:45, Rakesh v <www.rakeshv....@gmail.com> wrote: > Hello Ivan > > We upgrade only when critical security patch is released like meltdown and > L1TF else we don't do upgrades for every single kernel release > > Sent from my iPhone > > > On 13-Dec-2018, at 11:05 PM, Ivan Kudryavtsev <kudryavtsev...@bw-sw.com> > wrote: > > > > Rakesh, > > No magic exists. Migrate forth, reboot, and migrate back. What I'm really > > wondering about is why you upgrade every time, Ubuntu releases a new > > kernel... There are a pretty small amount of fixes related to KVM and > hosts > > are located in the private networks, they are single-tenant. Maybe you > just > > have to change to policy for that? > > > > чт, 13 дек. 2018 г. в 16:54, Rakesh v <www.rakeshv....@gmail.com>: > > > >> Hello Folks > >> > >> I have a question regarding upgrading OS on hypervisor. We have few > >> platforms with around 200 hypervisors in each platforms. Every time a > new > >> Ubuntu kernel comes in with new security patch like L1TF fix or other , > we > >> need to upgrade kernel on all hypervisors. Before rebooting hypervisor > we > >> enable maintenance on it so that all vm's are migrated away. During this > >> maintenance we always see some Network interruptions because of live > >> migrations. > >> > >> How are you guys handling such situations and how are doing the OS > >> upgrades? If you have some suggestions or using some automation tools > then > >> please let know > >> > >> I want to reduce time taken to upgrade all hypervisors without any > impact > >> to Networks or VM's > >> > >> Sent from my iPhone > > > > > > > > -- > > With best regards, Ivan Kudryavtsev > > Bitworks LLC > > Cell RU: +7-923-414-1515 > > Cell USA: +1-201-257-1512 > > WWW: http://bitworks.software/ <http://bw-sw.com/> > -- Andrija Panić
