Previously we described how to set up post-copy live migration in OpenStack Icehouse (and it should not be a problem to set it up in the same way in Juno). Naturally, we were curious to see how it performs. In this blog post we focus on performance analysis of post-copy live migration in Openstack Icehouse using QEMU / KVM with libvirt. Continue reading
We have shed blood, sweat and tears trying to get post-copy live migration working in OpenStack over the last month: this blogpost explains all the necessary steps to make it work and hopefully it will save future post-copy pioneers some pain. In our previous blog post we focused on setting it up in QEMU. This time we consider the bigger picture spanning all the levels of Openstack from system kernel requirements to setting up the right flags in the Nova configuration file in the OpenStack environments running QEMU / KVM with Libvirt. Continue reading
In our previous work we presented the performance of live migration in Openstack Icehouse using various types of VM flavors, its memory load and also examined how it performs in network and CPU loaded environment (see our previous posts –performance of live migration, performance of block live migration, performance of both under varying cpu and network load). One factor which was not considered in our earlier work is the impact of VM ephemeral disk size on the performance of the live migration. That is the focus of this post. Continue reading
Previously, we analyzed the performance of virtual machine (VM) live migration in different scenarios under Openstack Icehouse. Until now, all our experiments were performed on essentially unloaded servers – clearly, this means that the results are not so widely applicable. Here, we analyze how the addition of load to the physical hosts and the network impacts the behaviour of both block live migration (BLM) and live migration (LM). (Note that the main difference is that BLM migrates the VM disk via the network while LM uses shared storage between source and destination hosts and the disk is not migrated at all). Continue reading
We continue our recent work regarding an analysis of the performance of live migration in Openstack Icehouse. Our previous results focused on block live migration in Openstack, without shared storage configured between computing nodes. In this post we focus on the performance of live migration in the system with a shared file system configured, compare it with block live migration and try to determine scenarios more suitable for each approach. Continue reading
Since our servers have been set up for live migration with Openstack Icehouse, we wondered how live migration would perform. We measured the duration of the migration process, VM downtime duration and the amount of data transfered via the ethernet during a live migration. All tests were performed across 5 different VM flavors to examine the impact of the flavor. Another point we were curious about is how higher memory load of VMs can impact migration performance. Here, we present the results of our experiments which show how live mgration works in these different scenarios.
[Update 8.12.2014] Since OpenStack’s Juno release hasn’t introduced any changes regarding live migration, Juno users should be able to follow this tutorial as well as the Icehouse users. If you experience any issues let us know. The same setup can be used for newer versions of QEMU and Libvirt as well. Currently we are using QEMU 2.1.5 with Libvirt 1.2.11.
The Green IT theme here in ICCLab is working on monitoring and reducing datacenter energy consumption by leveraging Openstack’s live migration feature. We’ve already experimented a little with live migration in the Havana release (mostly with no luck), but since live migration is touted as one of the new stable features in the Icehouse release, we decided to investigate how it has evolved. This blogpost, largely based on official Openstack documentation, provides step-by-step walkthrough of how to setup and perform virtual machine live migration with servers running the Openstack Icehouse release and KVM/QEMU hypervisor with libvirt.
Virtual machine (VM) live migration is a process, where a VM instance, comprising of its states, memory and emulated devices, is moved from one hypervisor to another with ideally no downtime. It can come handy in many situations such as basic system maintenance, VM consolidation and more complex load management systems designed to reduce data center energy consumption. Continue reading
The release of Icehouse brought a few enhancements that were of particular interest in our work – notably Ceilometer/Telemetry developments both in terms of data models as well as performance and improved support for live VM migration. As we had a positive experience with installing Openstack using Mirantis Openstack 4.x (based on Fuel 4.x), we thought it would be worth having a go at upgrading to Icehouse with Mirantis Openstack 5.0 (of which Fuel 5.0 is a key component) on a small set of servers. Here’s a short note on how it worked out.