diff --git a/doc/Pacemaker_Remote/en-US/Ch-Baremetal-Tutorial.txt b/doc/Pacemaker_Remote/en-US/Ch-Baremetal-Tutorial.txt index 9bf6dc6c20..d0fd14b02f 100644 --- a/doc/Pacemaker_Remote/en-US/Ch-Baremetal-Tutorial.txt +++ b/doc/Pacemaker_Remote/en-US/Ch-Baremetal-Tutorial.txt @@ -1,230 +1,230 @@ = Baremetal Walk-through = +What this tutorial is:+ This tutorial is an in-depth walk-through of how to get pacemaker to integrate a baremetal remote-node into the cluster as a node capable of running cluster resources. +What this tutorial is not:+ This tutorial is not a realistic deployment scenario. The steps shown here are meant to get users familiar with the concept of remote-nodes as quickly as possible. This tutorial requires three machines. Two machines to act as cluster-nodes and a third to act as the baremetal remote-node. This tutorial was tested using Fedora 20 on both the cluster-nodes and baremetal remote-node. Anything that is capable of running pacemaker v1.1.11 or greater will do though. An installation guide for installing Fedora 20 can be found here, http://docs.fedoraproject.org/en-US/Fedora/20/html/Installation_Guide/. Fedora 20 (or similar distro) host preparation steps. == SElinux and Firewall Considerations == In order to simply this tutorial we will disable selinux and the firewall on all the nodes. +WARNING:+ These actions will open a significant security threat to machines exposed to the outside world. [source,C] ---- # setenforce 0 # sed -i.bak "s/SELINUX=enforcing/SELINUX=permissive/g" /etc/selinux/config # firewall-cmd --add-port 3121/tcp --permanent # systemctl disable iptables.service # systemctl disable ip6tables.service # rm '/etc/systemd/system/basic.target.wants/iptables.service' # rm '/etc/systemd/system/basic.target.wants/ip6tables.service' # systemctl stop iptables.service # systemctl stop ip6tables.service ---- == Setup Pacemaker Remote on Baremetal remote-node == On the baremetal remote-node machine run these commands to generate an authkey and copy it to the /etc/pacemaker folder. [source,C] ---- # mkdir /etc/pacemaker # dd if=/dev/urandom of=/etc/pacemaker/authkey bs=4096 count=1 ---- Make sure to distribute this key to both of the cluster-nodes as well. All the nodes must have the same /etc/pacemaker/authkey installed for the communication to work correctly. Now install and start the pacemaker_remote daemon on the baremetal remote-node. [source,C] ---- -# yum install -y paceamaker-remote resource-agents pcs +# yum install -y pacemaker-remote resource-agents pcs # systemctl enable pacemaker_remote.service # systemctl start pacemaker_remote.service ---- Verify the start is successful. [source,C] ---- # systemctl status pacemaker_remote pacemaker_remote.service - Pacemaker Remote Service Loaded: loaded (/usr/lib/systemd/system/pacemaker_remote.service; enabled) Active: active (running) since Thu 2013-03-14 18:24:04 EDT; 2min 8s ago Main PID: 1233 (pacemaker_remot) CGroup: name=systemd:/system/pacemaker_remote.service └─1233 /usr/sbin/pacemaker_remoted Mar 14 18:24:04 remote1 systemd[1]: Starting Pacemaker Remote Service... Mar 14 18:24:04 remote1 systemd[1]: Started Pacemaker Remote Service. Mar 14 18:24:04 remote1 pacemaker_remoted[1233]: notice: lrmd_init_remote_tls_server: Starting a tls listener on port 3121. ---- == Verify cluster-node Connection to baremetal-node == Before moving forward it's worth going ahead and verifying the cluster-nodes can contact the baremetal node on port 3121. Here's a trick you can use. Connect using telnet from each of the cluster-nodes. The connection will get destroyed, but how it is destroyed tells you whether it worked or not. First add the baremetal remote-node's hostname (we're using remote1 in this tutorial) to the cluster-nodes' /etc/hosts files if you haven't already. This is required unless you have dns setup in a way where remote1's address can be discovered. Execute the following on each cluster-node, replacing the ip address with the actual ip address of the baremetal remote-node. [source,C] ---- # cat << END >> /etc/hosts 192.168.122.10 remote1 END ---- If running the telnet command on one of the cluster-nodes results in this output before disconnecting, the connection works. [source,C] ---- # telnet remote1 3121 Trying 192.168.122.10... Connected to remote1. Escape character is '^]'. Connection closed by foreign host. ---- If you see this, the connection is not working. [source,C] ---- # telnet remote1 3121 Trying 192.168.122.10... telnet: connect to address 192.168.122.10: No route to host ---- Once you can successfully connect to the baremetal remote-node from the both cluster-nodes, move on to setting up pacemaker on the cluster-nodes. == Install cluster-node Software == On the two cluster-nodes install the following packages. [source,C] ---- # yum install -y pacemaker corosync pcs resource-agents ---- == Setup Corosync on cluster-nodes == Corosync handles pacemaker's cluster membership and messaging. The corosync config file is located in /etc/corosync/corosync.conf. That config file must be initialized with information about the two cluster-nodes before pacemaker can start. To initialize the corosync config file, execute the following pcs command on both nodes filling in the information in <> with your nodes' information. [source,C] ---- # pcs cluster setup --local mycluster ---- A recent syntax change in pcs may cause the above command to fail. If so try this alternative. [source,C] ---- # pcs cluster setup --force --local --name mycluster ---- == Start Pacemaker on cluster-nodes == Start the cluster stack on both cluster nodes using the following command. [source,C] ---- # pcs cluster start ---- Verify corosync membership [source,C] ---- # pcs status corosync Membership information Nodeid Votes Name 1795270848 1 node1 (local) ---- Verify pacemaker status. At first the 'pcs cluster status' output will look like this. [source,C] ---- # pcs status Last updated: Thu Mar 14 12:26:00 2013 Last change: Thu Mar 14 12:25:55 2013 via crmd on example-host Stack: corosync Current DC: Version: 1.1.11 1 Nodes configured, unknown expected votes 0 Resources configured. ---- After about a minute you should see your two cluster-nodes come online. [source,C] ---- # pcs status Last updated: Thu Mar 14 12:28:23 2013 Last change: Thu Mar 14 12:25:55 2013 via crmd on node1 Stack: corosync Current DC: node1 (1795270848) - partition with quorum Version: 1.1.11 2 Nodes configured, unknown expected votes 0 Resources configured. Online: [ node1 node2 ] ---- For the sake of this tutorial, we are going to disable stonith to avoid having to cover fencing device configuration. [source,C] ---- # pcs property set stonith-enabled=false ---- == Integrate Baremetal remote-node into Cluster == Integrating a baremetal remote-node into the cluster is achieved through the creation of a remote-node connection resource. The remote-node connection resource both establishes the connection to the remote-node and defines that the remote-node exists. Note that this resource is actually internal to Pacemaker's crmd component. A metadata file for this resource can be found in the /usr/lib/ocf/resource.d/pacemaker/remote file that describes what options are available, but there is no actual ocf:pacemaker:remote resource agent script that performs any work. Define the remote-node connection resource to our baremetal remote-node, remote1, using the following command. [source,C] ---- # pcs resource create remote1 ocf:pacemaker:remote ---- That's it. After a moment you should see the remote-node come online. [source,C] ---- Last updated: Fri Oct 18 18:47:21 2013 Last change: Fri Oct 18 18:46:14 2013 via cibadmin on node1 Stack: corosync Current DC: node1 (1) - partition with quorum Version: 1.1.11 3 Nodes configured 1 Resources configured Online: [ node1 node2 ] RemoteOnline: [ remote1 ] remote1 (ocf::pacemaker:remote): Started node1 ---- == Starting Resources on baremetal remote-node == +"Warning: Never involve a remote-node connection resource in a resource group, colocation, or order constraint"+ Once the baremetal remote-node is integrated into the cluster, starting resources on a baremetal remote-node is the exact same as the cluster nodes. Refer to the Clusters from Scratch document for examples on resource creation. http://clusterlabs.org/doc/ == Fencing baremetal remote-nodes == The cluster understands how to fence baremetal remote-nodes and can use standard fencing devices to do so. No special considerations are required. Note however that remote-nodes can never initiate a fencing action. Only cluster-nodes are capable of actually executing the fencing operation on another node. == Accessing Cluster Tools from a Baremetal remote-node == Besides allowing the cluster to manage resources on a remote-node, pacemaker_remote has one other trick. +The pacemaker_remote daemon allows nearly all the pacemaker tools (crm_resource, crm_mon, crm_attribute, crm_master) to work on remote nodes natively.+ Try it, run +crm_mon+ or +pcs status+ on the baremetal node after pacemaker has integrated the remote-node into the cluster. These tools just work. These means resource agents such as master/slave resources which need access to tools like crm_master work seamlessly on the remote-nodes. diff --git a/doc/Pacemaker_Remote/en-US/Ch-Intro.txt b/doc/Pacemaker_Remote/en-US/Ch-Intro.txt index d8699b3acf..c18db25bcf 100644 --- a/doc/Pacemaker_Remote/en-US/Ch-Intro.txt +++ b/doc/Pacemaker_Remote/en-US/Ch-Intro.txt @@ -1,85 +1,85 @@ = Extending High Availability Cluster into Virtual Nodes = == Overview == The recent addition of the +pacemaker_remote+ service supported by +Pacemaker version 1.1.10 and greater+ allows nodes not running the cluster stack (pacemaker+corosync) to integrate into the cluster and have the cluster manage their resources just as if they were a real cluster node. This means that pacemaker clusters are now capable of managing both launching virtual environments (KVM/LXC) as well as launching the resources that live within those virtual environments without requiring the virtual environments to run pacemaker or corosync. == Terms == +cluster-node+ - A node running the High Availability stack (pacemaker + corosync) +remote-node+ - A node running pacemaker_remote without the rest of the High Availability stack. There are two types of remote-nodes, container and baremetal. +container+ - A pacemaker resource that contains additional resources. For example, a KVM virtual machine resource that contains a webserver resource. +container remote-node+ - A virtual guest remote-node running the pacemaker_remote service. This describes a specific remote-node use case where a virtual guest resource managed by the cluster is both started by the cluster and integrated into the cluster as a remote-node. +baremetal+ - Term used to describe an environment that is not virtualized. +baremetal remote-node+ - A baremetal hardware node running pacemaker_remote. This describes a specific remote-node use case where a hardware node not running the High Availability stack is integrated into the cluster as a remote-node through the use of pacemaker_remote. +pacemaker_remote+ - A service daemon capable of performing remote application management within guest nodes (baremetal, kvm, and lxc) in both pacemaker cluster environments and standalone (non-cluster) environments. This service is an enhanced version of pacemaker's local resource manage daemon (LRMD) that is capable of managing and monitoring LSB, OCF, upstart, and systemd resources on a guest remotely. It also allows for most of pacemaker's cli tools (crm_mon, crm_resource, crm_master, crm_attribute, ect..) to work natively on remote-nodes. +LXC+ - A Linux Container defined by the libvirt-lxc Linux container driver. http://libvirt.org/drvlxc.html == Version Info == This feature is in ongoing development. +Pacemaker v1.1.10+ * Initial pacemaker_remote daemon and integration support. * Only supports pacemaker in KVM/LXC environments. * pacemaker_remote daemon unit test suite. * Known bugs include (These are likely resolved if you have received an 1.1.10.x point release): Errors when setting remote-node attributes, Failures when stopping orphaned (deleted from cib while running) remote-nodes, Fixes remote-node usage in asymmetric clusters. +Currently in Master github branch and scheduled for Pacemaker v1.1.11+ * Baremetal remote-node support. * Improvements to scaling remote-node integration. Performance testing here included 16 cluster nodes running 64 remote-nodes living in LXC containers. As part of this testing, several performance enhancements were introduced into the integration code. * CTS tests. RemoteLXC and RemoteBaremetal. These two CTS tests allow us to perform automated verification of pacemaker_remote integration. * Fixes for known bugs in 1.1.10 release. == Virtual Machine Use Case == The use of pacemaker_remote in virtual machines solves a deployment scenario that has traditionally been difficult to solve. +"I want a pacemaker cluster to manage virtual machine resources, but I also want pacemaker to be able to manage the resources that live within those virtual machines."+ In the past, users desiring this deployment had to make a decision. They would either have to sacrifice the ability of monitoring resources residing within virtual guests by running the cluster stack on the baremetal nodes, or run another cluster instance on the virtual guests where they potentially run into corosync scalability issues. There is a third scenario where the virtual guests run the cluster stack and join the same network as the baremetal nodes, but that can quickly hit issues with scalability as well. With the pacemaker_remote service we have a new option. -* The baremetal cluster-nodes run the cluster stack (paceamaker+corosync). +* The baremetal cluster-nodes run the cluster stack (pacemaker+corosync). * The virtual remote-nodes run the pacemaker_remote service (nearly zero configuration required on the virtual machine side) * The cluster stack on the cluster-nodes launch the virtual machines and immediately connect to the pacemaker_remote service, allowing the virtual machines to integrate into the cluster just as if they were a real cluster-node. The key difference here between the virtual machine remote-nodes and the cluster-nodes is that the remote-nodes are not running the cluster stack. This means the remote nodes will never become the DC, and they do not take place in quorum. On the other hand this also means that remote-nodes are not bound to the scalability limits associated with the cluster stack either. +No 16 node corosync member limits+ to deal with. That isn't to say remote-nodes can scale indefinitely, but it is known that remote-nodes scale horizontally much further than cluster-nodes. Other than the quorum limitation, these remote-nodes behave just like cluster nodes in respects to resource management. The cluster is fully capable of managing and monitoring resources on each remote-node. You can build constraints against remote-nodes, put them in standby, or whatever else you'd expect to be able to do with normal cluster-nodes. They even show up in the crm_mon output as you would expect cluster-nodes to. To solidify the concept, below is an example deployment that is very similar to an actual deployment we test in our developer environment to verify remote-node scalability. * 16 cluster-nodes running corosync+pacemaker stack. * 64 pacemaker managed virtual machine resources running pacemaker_remote configured as remote-nodes. * 64 pacemaker managed webserver and database resources configured to run on the 64 remote-nodes. With this deployment you would have 64 webservers and databases running on 64 virtual machines on 16 hardware nodes all of which are managed and monitored by the same pacemaker deployment. It is known that pacemaker_remote can scale to these lengths and possibly much further depending on the specific scenario. == Baremetal remote-node Use Case == +"I want my traditional High Availability cluster to scale beyond the limits imposed by the corosync messaging layer."+ Ultimately the primary advantage of baremetal remote-nodes over traditional nodes running the Corosync+Pacemaker stack is scalability. There are likely some other use cases related to geographically distributed HA clusters that baremetal remote-nodes may serve a purpose in, but those use cases not well understood at this point. The only limitations baremetal remote-nodes have that cluster-nodes do not is the ability to take place in cluster quorum, and the ability to execute fencing agents via stonith. That is not to say however that fencing of a baremetal node works any differently than that of a normal cluster-node. The Pacemaker policy engine understands how to fence baremetal remote-nodes. As long as a fencing device exists, the cluster is capable of ensuring baremetal nodes are fenced in the exact same way as normal cluster-nodes are fenced. == Linux Container Use Case == +I want to isolate and limit the system resources (cpu, memory, filesystem) a cluster resource can consume without using virtual machines.+ Using pacemaker_remote with Linux containers (libvirt-lxc) opens up some interesting possibilities for isolating resources in the cluster without the use of a hypervisor. We now have the ability to both define a contained environment with cpu and memory utilization limits and then assign resources to that contained environment all managed from within pacemaker. The LXC Walk-through section of this document outlines how pacemaker_remote can be used to bring Linux containers into the cluster as remote-nodes capable of executing resources. == Expanding the Cluster Stack == === Traditional HA Stack === image::images/pcmk-ha-cluster-stack.png["The Traditional Pacemaker Corosync HA Stack.",width="17cm",height="9cm",align="center"] === Remote-Node Enabled HA Stack Using Virtual guest nodes === image::images/pcmk-ha-remote-stack.png["Placing Pacemaker Remote into the Traditional HA Stack.",width="20cm",height="10cm",align="center"] diff --git a/doc/Pacemaker_Remote/en-US/Ch-KVM-Tutorial.txt b/doc/Pacemaker_Remote/en-US/Ch-KVM-Tutorial.txt index adf3422cb3..7b150aa5ef 100644 --- a/doc/Pacemaker_Remote/en-US/Ch-KVM-Tutorial.txt +++ b/doc/Pacemaker_Remote/en-US/Ch-KVM-Tutorial.txt @@ -1,467 +1,467 @@ = KVM Walk-through = +What this tutorial is:+ This tutorial is an in-depth walk-through of how to get pacemaker to manage a KVM guest instance and integrate that guest into the cluster as a remote-node. +What this tutorial is not:+ This tutorial is not a realistic deployment scenario. The steps shown here are meant to get users familiar with the concept of remote-nodes as quickly as possible. == Step 1: Setup the Host == This tutorial was created using Fedora 20 on the host and guest nodes. Anything that is capable of running libvirt and pacemaker v1.1.10 or greater will do though. An installation guide for installing Fedora 20 can be found here, http://docs.fedoraproject.org/en-US/Fedora/20/html/Installation_Guide/. Fedora 20 (or similar distro) host preparation steps. === SElinux and Firewall === In order to simply this tutorial we will disable the selinux and the firewall on the host. +WARNING:+ These actions will open a significant security threat to machines exposed to the outside world. [source,C] ---- # setenforce 0 # sed -i.bak "s/SELINUX=enforcing/SELINUX=permissive/g" /etc/selinux/config # systemctl disable iptables.service # systemctl disable ip6tables.service # rm '/etc/systemd/system/basic.target.wants/iptables.service' # rm '/etc/systemd/system/basic.target.wants/ip6tables.service' # systemctl stop iptables.service # systemctl stop ip6tables.service ---- === Install Cluster Software === [source,C] ---- # yum install -y pacemaker corosync pcs resource-agents ---- === Setup Corosync === Corosync handles pacemaker's cluster membership and messaging. The corosync config file is located in /etc/corosync/corosync.conf. That config file must be initialized with information about the cluster-nodes before pacemaker can start. To initialize the corosync config file, execute the following pcs command on both nodes filling in the information in <> with your nodes' information. [source,C] ---- # pcs cluster setup --local mycluster ---- A recent syntax change in pcs may cause the above command to fail. If so try this alternative. [source,C] ---- # pcs cluster setup --force --local --name mycluster ---- === Verify Cluster Software === Start the cluster [source,C] ---- # pcs cluster start ---- Verify corosync membership [source,C] ---- # pcs status corosync Membership information Nodeid Votes Name 1795270848 1 example-host (local) ---- Verify pacemaker status. At first the 'pcs cluster status' output will look like this. [source,C] ---- # pcs status Last updated: Thu Mar 14 12:26:00 2013 Last change: Thu Mar 14 12:25:55 2013 via crmd on example-host Stack: corosync Current DC: Version: 1.1.10 1 Nodes configured, unknown expected votes 0 Resources configured. ---- After about a minute you should see your host as a single node in the cluster. [source,C] ---- # pcs status Last updated: Thu Mar 14 12:28:23 2013 Last change: Thu Mar 14 12:25:55 2013 via crmd on example-host Stack: corosync Current DC: example-host (1795270848) - partition WITHOUT quorum Version: 1.1.8-9b13ea1 1 Nodes configured, unknown expected votes 0 Resources configured. Online: [ example-host ] ---- Go ahead and stop the cluster for now after verifying everything is in order. [source,C] ---- # pcs cluster stop ---- === Install Virtualization Software === [source,C] ---- # yum install -y kvm libvirt qemu-system qemu-kvm bridge-utils virt-manager # systemctl enable libvirtd.service ---- reboot the host == Step2: Create the KVM guest == I am not going to outline the installation steps required to create a kvm guest. There are plenty of tutorials available elsewhere that do that. I recommend using a Fedora 18 or greater distro as your guest as that is what I am testing this tutorial with. === Setup Guest Network === Run the commands below to set up a static ip address (192.168.122.10) and hostname (guest1). [source,C] ---- export remote_hostname=guest1 export remote_ip=192.168.122.10 export remote_gateway=192.168.122.1 yum remove -y NetworkManager rm -f /etc/hostname cat << END >> /etc/hostname $remote_hostname END hostname $remote_hostname cat << END >> /etc/sysconfig/network HOSTNAME=$remote_hostname GATEWAY=$remote_gateway END sed -i.bak "s/.*BOOTPROTO=.*/BOOTPROTO=none/g" /etc/sysconfig/network-scripts/ifcfg-eth0 cat << END >> /etc/sysconfig/network-scripts/ifcfg-eth0 IPADDR0=$remote_ip PREFIX0=24 GATEWAY0=$remote_gateway DNS1=$remote_gateway END systemctl restart network systemctl enable network.service systemctl enable sshd systemctl start sshd echo "checking connectivity" ping www.google.com ---- To simplify the tutorial we'll go ahead and disable selinux on the guest. We'll also need to poke a hole through the firewall on port 3121 (the default port for pacemaker_remote) so the host can contact the guest. [source,C] ---- # setenforce 0 # sed -i.bak "s/SELINUX=enforcing/SELINUX=permissive/g" /etc/selinux/config # firewall-cmd --add-port 3121/tcp --permanent ---- If you still encounter connection issues just disable iptables and ipv6tables on the guest like we did on the host to guarantee you'll be able to contact the guest from the host. At this point you should be able to ssh into the guest from the host. === Setup Pacemaker Remote === On the +HOST+ machine run these commands to generate an authkey and copy it to the /etc/pacemaker folder on both the host and guest. [source,C] ---- # mkdir /etc/pacemaker # dd if=/dev/urandom of=/etc/pacemaker/authkey bs=4096 count=1 # scp -r /etc/pacemaker root@192.168.122.10:/etc/ ---- Now on the +GUEST+ install pacemaker-remote package and enable the daemon to run at startup. In the commands below you will notice the 'pacemaker' and 'pacemaker_remote' packages are being installed. The 'pacemaker' package is not required. The only reason it is being installed for this tutorial is because it contains the a 'Dummy' resource agent we will be using later on to test the remote-node. [source,C] ---- -# yum install -y pacemaker paceamaker-remote resource-agents +# yum install -y pacemaker pacemaker-remote resource-agents # systemctl enable pacemaker_remote.service ---- Now start pacemaker_remote on the guest and verify the start was successful. [source,C] ---- # systemctl start pacemaker_remote.service # systemctl status pacemaker_remote pacemaker_remote.service - Pacemaker Remote Service Loaded: loaded (/usr/lib/systemd/system/pacemaker_remote.service; enabled) Active: active (running) since Thu 2013-03-14 18:24:04 EDT; 2min 8s ago Main PID: 1233 (pacemaker_remot) CGroup: name=systemd:/system/pacemaker_remote.service └─1233 /usr/sbin/pacemaker_remoted Mar 14 18:24:04 guest1 systemd[1]: Starting Pacemaker Remote Service... Mar 14 18:24:04 guest1 systemd[1]: Started Pacemaker Remote Service. Mar 14 18:24:04 guest1 pacemaker_remoted[1233]: notice: lrmd_init_remote_tls_server: Starting a tls listener on port 3121. ---- === Verify Host Connection to Guest === Before moving forward it's worth going ahead and verifying the host can contact the guest on port 3121. Here's a trick you can use. Connect using telnet from the host. The connection will get destroyed, but how it is destroyed tells you whether it worked or not. First add guest1 to the host machine's /etc/hosts file if you haven't already. This is required unless you have dns setup in a way where guest1's address can be discovered. [source,C] ---- # cat << END >> /etc/hosts 192.168.122.10 guest1 END ---- If running the telnet command on the host results in this output before disconnecting, the connection works. [source,C] ---- # telnet guest1 3121 Trying 192.168.122.10... Connected to guest1. Escape character is '^]'. Connection closed by foreign host. ---- If you see this, the connection is not working. [source,C] ---- # telnet guest1 3121 Trying 192.168.122.10... telnet: connect to address 192.168.122.10: No route to host ---- Once you can successfully connect to the guest from the host, shutdown the guest. Pacemaker will be managing the virtual machine from this point forward. == Step3: Integrate KVM guest into Cluster. == Now the fun part, integrating the virtual machine you've just created into the cluster. It is incredibly simple. === Start the Cluster === On the host, start pacemaker. [source,C] ---- # pcs cluster start ---- Wait for the host to become the DC. The output of 'pcs status' should look similar to this after about a minute. [source,C] ---- Last updated: Thu Mar 14 16:41:22 2013 Last change: Thu Mar 14 16:41:08 2013 via crmd on example-host Stack: corosync Current DC: example-host (1795270848) - partition WITHOUT quorum Version: 1.1.10 1 Nodes configured, unknown expected votes 0 Resources configured. Online: [ example-host ] ---- Now enable the cluster to work without quorum or stonith. This is required just for the sake of getting this tutorial to work with a single cluster-node. [source,C] ---- # pcs property set stonith-enabled=false # pcs property set no-quorum-policy=ignore ---- === Integrate KVM Guest as remote-node === If you didn't already do this earlier in the verify host to guest connection section, add the KVM guest's ip to the host's /etc/hosts file so we can connect by hostname. The command below will do that if you used the same ip address I used earlier. [source,C] ---- # cat << END >> /etc/hosts 192.168.122.10 guest1 END ---- We will use the +VirtualDomain+ resource agent for the management of the virtual machine. This agent requires the virtual machine's xml config to be dumped to a file on disk. To do this pick out the name of the virtual machine you just created from the output of this list. [source,C] ---- # virsh list --all Id Name State ______________________________________________ - guest1 shut off ---- In my case I named it guest1. Dump the xml to a file somewhere on the host using the following command. [source,C] ---- # virsh dumpxml guest1 > /root/guest1.xml ---- Now just register the resource with pacemaker and you're set! [source,C] ---- # pcs resource create vm-guest1 VirtualDomain hypervisor="qemu:///system" config="/root/guest1.xml" meta remote-node=guest1 ---- Once the 'vm-guest1' resource is started you will see 'guest1' appear in the 'pcs status' output as a node. The final 'pcs status' output should look something like this. [source,C] ---- Last updated: Fri Mar 15 09:30:30 2013 Last change: Thu Mar 14 17:21:35 2013 via cibadmin on example-host Stack: corosync Current DC: example-host (1795270848) - partition WITHOUT quorum Version: 1.1.10 2 Nodes configured, unknown expected votes 2 Resources configured. Online: [ example-host guest1 ] Full list of resources: vm-guest1 (ocf::heartbeat:VirtualDomain): Started example-host ---- === Starting Resources on KVM Guest === The commands below demonstrate how resources can be executed on both the remote-node and the cluster-node. Create a few Dummy resources. Dummy resources are real resource agents used just for testing purposes. They actually execute on the host they are assigned to just like an apache server or database would, except their execution just means a file was created. When the resource is stopped, that the file it created is removed. [source,C] ---- # pcs resource create FAKE1 ocf:pacemaker:Dummy # pcs resource create FAKE2 ocf:pacemaker:Dummy # pcs resource create FAKE3 ocf:pacemaker:Dummy # pcs resource create FAKE4 ocf:pacemaker:Dummy # pcs resource create FAKE5 ocf:pacemaker:Dummy ---- Now check your 'pcs status' output. In the resource section you should see something like the following, where some of the resources got started on the cluster-node, and some started on the remote-node. [source,C] ---- Full list of resources: vm-guest1 (ocf::heartbeat:VirtualDomain): Started example-host FAKE1 (ocf::pacemaker:Dummy): Started guest1 FAKE2 (ocf::pacemaker:Dummy): Started guest1 FAKE3 (ocf::pacemaker:Dummy): Started example-host FAKE4 (ocf::pacemaker:Dummy): Started guest1 FAKE5 (ocf::pacemaker:Dummy): Started example-host ---- The remote-node, 'guest1', reacts just like any other node in the cluster. For example, pick out a resource that is running on your cluster-node. For my purposes I am picking FAKE3 from the output above. We can force FAKE3 to run on 'guest1' in the exact same way we would any other node. [source,C] ---- # pcs constraint FAKE3 prefers guest1 ---- Now looking at the bottom of the 'pcs status' output you'll see FAKE3 is on 'guest1'. [source,C] ---- Full list of resources: vm-guest1 (ocf::heartbeat:VirtualDomain): Started example-host FAKE1 (ocf::pacemaker:Dummy): Started guest1 FAKE2 (ocf::pacemaker:Dummy): Started guest1 FAKE3 (ocf::pacemaker:Dummy): Started guest1 FAKE4 (ocf::pacemaker:Dummy): Started example-host FAKE5 (ocf::pacemaker:Dummy): Started example-host ---- === Testing Remote-node Recovery and Fencing === Pacemaker's policy engine is smart enough to know fencing remote-nodes associated with a virtual machine means shutting off/rebooting the virtual machine. No special configuration is necessary to make this happen. If you are interested in testing this functionality out, trying stopping the guest's pacemaker_remote daemon. This would be equivalent of abruptly terminating a cluster-node's corosync membership without properly shutting it down. ssh into the guest and run this command. [source,C] ---- # kill -9 `pidof pacemaker_remoted` ---- After a few seconds or so you'll see this in your 'pcs status' output. The 'guest1' node will be show as offline as it is being recovered. [source,C] ---- Last updated: Fri Mar 15 11:00:31 2013 Last change: Fri Mar 15 09:54:16 2013 via cibadmin on example-host Stack: corosync Current DC: example-host (1795270848) - partition WITHOUT quorum Version: 1.1.10 2 Nodes configured, unknown expected votes 7 Resources configured. Online: [ example-host ] OFFLINE: [ guest1 ] Full list of resources: vm-guest1 (ocf::heartbeat:VirtualDomain): Started example-host FAKE1 (ocf::pacemaker:Dummy): Stopped FAKE2 (ocf::pacemaker:Dummy): Stopped FAKE3 (ocf::pacemaker:Dummy): Stopped FAKE4 (ocf::pacemaker:Dummy): Started example-host FAKE5 (ocf::pacemaker:Dummy): Started example-host Failed actions: guest1_monitor_30000 (node=example-host, call=3, rc=7, status=complete): not running ---- Once recovery of the guest is complete, you'll see it automatically get re-integrated into the cluster. The final 'pcs status' output should look something like this. [source,C] ---- Last updated: Fri Mar 15 11:03:17 2013 Last change: Fri Mar 15 09:54:16 2013 via cibadmin on example-host Stack: corosync Current DC: example-host (1795270848) - partition WITHOUT quorum Version: 1.1.10 2 Nodes configured, unknown expected votes 7 Resources configured. Online: [ example-host guest1 ] Full list of resources: vm-guest1 (ocf::heartbeat:VirtualDomain): Started example-host FAKE1 (ocf::pacemaker:Dummy): Started guest1 FAKE2 (ocf::pacemaker:Dummy): Started guest1 FAKE3 (ocf::pacemaker:Dummy): Started guest1 FAKE4 (ocf::pacemaker:Dummy): Started example-host FAKE5 (ocf::pacemaker:Dummy): Started example-host Failed actions: guest1_monitor_30000 (node=example-host, call=3, rc=7, status=complete): not running ---- === Accessing Cluster Tools from Remote-node === Besides just allowing the cluster to manage resources on a remote-node, pacemaker_remote has one other trick. +The pacemaker_remote daemon allows nearly all the pacemaker tools (crm_resource, crm_mon, crm_attribute, crm_master) to work on remote nodes natively.+ Try it, run +crm_mon+ or +pcs status+ on the guest after pacemaker has integrated the remote-node into the cluster. These tools just work. These means resource agents such as master/slave resources which need access to tools like crm_master work seamlessly on the remote-nodes.