[Pacemaker] Fencing libvirt/KVM nodes running on different hosts?
Hi, Scenario: two physical virtualisation hosts run various KVM-based virtual machines, managed by Libvirt. Two VMs, one on each host, form a Pacemaker cluster, say for a simple database server, using DRBD and a virtual/cluster IP address. Using Ubuntu 10.04 and Pacemaker 1.1.6, with Corosync 1.4.2 on the hosts and guests. How do I implement node-level fencing in this scenario? Can the rather new external/libvirt STONITH plugin be used here? It seems to me it only supports a single hypervisor URI to connect to and expects all VMs/nodes that can be fenced to be running on the same hypervisor. Looking at http://www.clusterlabs.org/wiki/Guest_Fencing it says that fencing guests running on multiple hosts is not supported in fence-virt/fence-virtd. What are my options here? How do other people manage node-level fencing/STONITH when the nodes are VMs and running on different physical hosts (which seems like the sensible thing to do, considering a single host is a SPOF)? Sorta related question: are Pacemaker clusters based on virtual machines (and Libvirt) really so uncommon that there isn't a quasi-definitive answer to this? Like If you use Libvirt, implement fencing by using this or that STONITH plugin. Thanks in advance, Andreas ___ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
Re: [Pacemaker] Fencing libvirt/KVM nodes running on different hosts?
On Tue, Nov 29, 2011 at 6:55 AM, Andreas Ntaflos d...@pseudoterminal.org wrote: Hi, Scenario: two physical virtualisation hosts run various KVM-based virtual machines, managed by Libvirt. Two VMs, one on each host, form a Pacemaker cluster, say for a simple database server, using DRBD and a virtual/cluster IP address. Using Ubuntu 10.04 and Pacemaker 1.1.6, with Corosync 1.4.2 on the hosts and guests. How do I implement node-level fencing in this scenario? Can the rather new external/libvirt STONITH plugin be used here? It seems to me it only supports a single hypervisor URI to connect to and expects all VMs/nodes that can be fenced to be running on the same hypervisor. Looking at http://www.clusterlabs.org/wiki/Guest_Fencing it says that fencing guests running on multiple hosts is not supported in fence-virt/fence-virtd. What are my options here? How do other people manage node-level fencing/STONITH when the nodes are VMs and running on different physical hosts (which seems like the sensible thing to do, considering a single host is a SPOF)? Sorta related question: are Pacemaker clusters based on virtual machines (and Libvirt) really so uncommon that there isn't a quasi-definitive answer to this? Like If you use Libvirt, implement fencing by using this or that STONITH plugin. You could try fence_xvm or fence_virt from the RHCS set of stonith agents (which pacemaker also supports). I believe it also handles the case when the guest could be on one of multiple hosts, personally I only use it for a single host. Lon might have some documentation pointers... Thanks in advance, Andreas ___ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org ___ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
Re: [Pacemaker] Fencing libvirt/KVM nodes running on different hosts?
28.11.2011 22:55, Andreas Ntaflos wrote: Hi, Scenario: two physical virtualisation hosts run various KVM-based virtual machines, managed by Libvirt. Two VMs, one on each host, form a Pacemaker cluster, say for a simple database server, using DRBD and a virtual/cluster IP address. Using Ubuntu 10.04 and Pacemaker 1.1.6, with Corosync 1.4.2 on the hosts and guests. How do I implement node-level fencing in this scenario? I use set of: * qpid server * libvirt-qpid on each host which runs VMs * fence-virtd with multicast listener * fence-virtd-libvirt-qpid (patched, patches were posted to pacemaker list 03.10.2011 for those who need it) * fence_xvm as a fencing agent Major problem I recently discovered is that you can have only one instance of fence_xvm process running (executing) on a node simultaneously, because it binds to predefined port. Best, Vladislav ___ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
