Dear Users!
This is to inform you that there will be a scheduled downtime of the 'metacloud-dukan' cluster, part of the physical resources in MetaCloud. This will be the last in a series of outages that were required to extend, improve and physically move our cloud infrastructure. The downtime well begin on 24 March and end on 27 March. All virtual machines running on nodes dukan{1..10}.ics.muni.cz will be stopped. During the outage, the hypervisor will change from XEN to KVM, finally unifying hypervisors used on all resources across MetaCloud.
How to tell if the outage affects your virtual machines
Use the OpenNebula dashboard to display a list of all your virtual machines (Virtual Resources → Virtual Machines). The 'Host' column shows the physical node name for each VM. The outage will affect all virtual machines on nodes dukan{1..10}.ics.muni.cz. You may also filter the contents of the VMs table using the Search box on the top of the page.
What will happen with my virtual machines during the outage
All affected VMs must be stopped. It will be a great help to us if you can stop your own machines before end of business on Monday, 23 March. Otherwise, we will stop you VMs and move them to storage as the downtime you will be able to start your machines again. Since the hypervisor will change from XEN to KVM, some machines may fail to start properly. Therefore, do not hesitate to contact us in case any of your VMs acts strangely. Unfortunately, it is not possible to check for compatibility with KVM beforehand, and can be only done experimentally. Standard MetaCentrum images, however, are already tuned for KVM and are expected to cope without glitches.
Thank you for your understanding. Be assured that this is the last planned downtime for the foreseeable future.
Best regards, MetaCloud