diff --git a/doc/Clusters_from_Scratch/en-US/Ch-Installation.txt b/doc/Clusters_from_Scratch/en-US/Ch-Installation.txt index 851fc08c94..fd82fd1194 100644 --- a/doc/Clusters_from_Scratch/en-US/Ch-Installation.txt +++ b/doc/Clusters_from_Scratch/en-US/Ch-Installation.txt @@ -1,489 +1,489 @@ = Installation = == Install &DISTRO; &DISTRO_VERSION; == === Boot the Install Image === Download the 4GB http://isoredirect.centos.org/centos/7/isos/x86_64/CentOS-7-x86_64-DVD-1503-01.iso[&DISTRO; &DISTRO_VERSION; DVD ISO]. Use the image to boot a virtual machine, or burn it to a DVD or USB drive and boot a physical server from that. After starting the installation, select your language and keyboard layout at the welcome screen. .&DISTRO; &DISTRO_VERSION; Installation Welcome Screen image::images/Welcome.png["Welcome to &DISTRO; &DISTRO_VERSION;",align="center",scaledwidth="100%"] === Installation Options === At this point, you get a chance to tweak the default installation options. .&DISTRO; &DISTRO_VERSION; Installation Summary Screen image::images/Installer.png["&DISTRO; &DISTRO_VERSION; Installation Summary",align="center",scaledwidth="100%"] Ignore the *SOFTWARE SELECTION* section (try saying that 10 times quickly). The *Infrastructure Server* environment does have add-ons with much of the software we need, but we will leave it as a *Minimal Install* here, so that we can see exactly what software is required later. === Configure Network === In the *NETWORK & HOSTNAME* section: - Edit *Host Name:* as desired. For this example, we will use *pcmk-1.localdomain*. - Select your network device, press *Configure...*, and manually assign a fixed IP address. For this example, we'll use 192.168.122.101 under *IPv4 Settings* (with an appropriate netmask, gateway and DNS server). - Flip the switch to turn your network device on. [IMPORTANT] =========== Do not accept the default network settings. Cluster machines should never obtain an IP address via DHCP, because DHCP's periodic address renewal will interfere with corosync. =========== === Configure Disk === By default, the installer's automatic partitioning will use LVM (which allows us to dynamically change the amount of space allocated to a given partition). However, it allocates all free space to the +/+ (aka. *root*) partition, which cannot be reduced in size later (dynamic increases are fine). In order to follow the DRBD and GFS2 portions of this guide, we need to reserve space on each machine for a replicated volume. Enter the *INSTALLATION DESTINATION* section, ensure the hard drive you want to install to is selected, select *I will configure partitioning*, and press *Done*. In the *MANUAL PARTITIONING* screen that comes next, click the option to create mountpoints automatically. Select the +/+ mountpoint, and reduce the desired capacity by 1GiB or so. Select *Modify...* by the volume group name, and change the *Size policy:* to *As large as possible*, to make the reclaimed space available inside the LVM volume group. We'll add the additional volume later. === Configure Time Synchronization === It is highly recommended to enable NTP on your cluster nodes. Doing so ensures all nodes agree on the current time and makes reading log files significantly easier. &DISTRO; will enable NTP automatically. If you want to change any time-related settings (such as time zone or NTP server), you can do this in the *TIME & DATE* section. === Finish Install === Select *Begin Installation*. Once it completes, set a root password, and reboot as instructed. For the purposes of this document, it is not necessary to create any additional users. After the node reboots, you'll see a login prompt on the console. Login using *root* and the password you created earlier. .&DISTRO; &DISTRO_VERSION; Console Prompt image::images/Console.png["&DISTRO; &DISTRO_VERSION; Console",align="center",scaledwidth="100%"] [NOTE] ====== From here on, we're going to be working exclusively from the terminal. ====== == Configure the OS == === Verify Networking === Ensure that the machine has the static IP address you configured earlier. ----- [root@pcmk-1 ~]# ip addr 1: lo: mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 52:54:00:d7:d6:08 brd ff:ff:ff:ff:ff:ff inet 192.168.122.101/24 brd 192.168.122.255 scope global eth0 valid_lft forever preferred_lft forever inet6 fe80::5054:ff:fed7:d608/64 scope link valid_lft forever preferred_lft forever ----- [NOTE] ===== If you ever need to change the node's IP address from the command line, follow these instructions, replacing *${device}* with the name of your network device: .... [root@pcmk-1 ~]# vi /etc/sysconfig/network-scripts/ifcfg-${device} # manually edit as desired [root@pcmk-1 ~]# nmcli dev disconnect ${device} [root@pcmk-1 ~]# nmcli con reload ${device} [root@pcmk-1 ~]# nmcli con up ${device} .... This makes *NetworkManager* aware that a change was made on the config file. ===== Next, ensure that the routes are as expected: ----- [root@pcmk-1 ~]# ip route default via 192.168.122.1 dev eth0 proto static metric 100 192.168.122.0/24 dev eth0 proto kernel scope link src 192.168.122.101 metric 100 ----- If there is no line beginning with *default via*, then you may need to add a line such as [source,Bash] GATEWAY="192.168.122.1" to the device configuration using the same process as described above for changing the IP address. Now, check for connectivity to the outside world. Start small by testing whether we can reach the gateway we configured. ----- [root@pcmk-1 ~]# ping -c 1 192.168.122.1 PING 192.168.122.1 (192.168.122.1) 56(84) bytes of data. 64 bytes from 192.168.122.1: icmp_req=1 ttl=64 time=0.249 ms --- 192.168.122.1 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.249/0.249/0.249/0.000 ms ----- Now try something external; choose a location you know should be available. ----- [root@pcmk-1 ~]# ping -c 1 www.google.com PING www.l.google.com (173.194.72.106) 56(84) bytes of data. 64 bytes from tf-in-f106.1e100.net (173.194.72.106): icmp_req=1 ttl=41 time=167 ms --- www.l.google.com ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 167.618/167.618/167.618/0.000 ms ----- === Login Remotely === The console isn't a very friendly place to work from, so we will now switch to accessing the machine remotely via SSH where we can use copy and paste, etc. From another host, check whether we can see the new host at all: ----- beekhof@f16 ~ # ping -c 1 192.168.122.101 PING 192.168.122.101 (192.168.122.101) 56(84) bytes of data. 64 bytes from 192.168.122.101: icmp_req=1 ttl=64 time=1.01 ms --- 192.168.122.101 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 1.012/1.012/1.012/0.000 ms ----- Next, login as root via SSH. ----- beekhof@f16 ~ # ssh -l root 192.168.122.101 The authenticity of host '192.168.122.101 (192.168.122.101)' can't be established. ECDSA key fingerprint is 6e:b7:8f:e2:4c:94:43:54:a8:53:cc:20:0f:29:a4:e0. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.122.101' (ECDSA) to the list of known hosts. root@192.168.122.101's password: Last login: Tue Aug 11 13:14:39 2015 [root@pcmk-1 ~]# ----- === Apply Updates === Apply any package updates released since your installation image was created: ---- [root@pcmk-1 ~]# yum update ---- === Use Short Node Names === During installation, we filled in the machine's fully qualified domain name (FQDN), which can be rather long when it appears in cluster logs and status output. See for yourself how the machine identifies itself: (((Nodes, short name))) ---- [root@pcmk-1 ~]# uname -n pcmk-1.localdomain ---- (((Nodes, Domain name (Query)))) We can use the `hostnamectl` tool to strip off the domain name: ---- [root@pcmk-1 ~]# hostnamectl set-hostname $(uname -n | sed s/\\..*//) ---- (((Nodes, Domain name (Remove from host name)))) Now, check that the machine is using the correct name: ---- [root@pcmk-1 ~]# uname -n pcmk-1 ---- == Repeat for Second Node == Repeat the Installation steps so far, so that you have two nodes ready to have the cluster software installed. For the purposes of this document, the additional node is called pcmk-2 with address 192.168.122.102. == Configure Communication Between Nodes == === Configure Host Name Resolution === Confirm that you can communicate between the two new nodes: ---- [root@pcmk-1 ~]# ping -c 3 192.168.122.102 PING 192.168.122.102 (192.168.122.102) 56(84) bytes of data. 64 bytes from 192.168.122.102: icmp_seq=1 ttl=64 time=0.343 ms 64 bytes from 192.168.122.102: icmp_seq=2 ttl=64 time=0.402 ms 64 bytes from 192.168.122.102: icmp_seq=3 ttl=64 time=0.558 ms --- 192.168.122.102 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2000ms rtt min/avg/max/mdev = 0.343/0.434/0.558/0.092 ms ---- Now we need to make sure we can communicate with the machines by their name. If you have a DNS server, add additional entries for the two machines. Otherwise, you'll need to add the machines to +/etc/hosts+ on both nodes. Below are the entries for my cluster nodes: ---- [root@pcmk-1 ~]# grep pcmk /etc/hosts 192.168.122.101 pcmk-1.clusterlabs.org pcmk-1 192.168.122.102 pcmk-2.clusterlabs.org pcmk-2 ---- We can now verify the setup by again using ping: ---- [root@pcmk-1 ~]# ping -c 3 pcmk-2 PING pcmk-2.clusterlabs.org (192.168.122.101) 56(84) bytes of data. 64 bytes from pcmk-1.clusterlabs.org (192.168.122.101): icmp_seq=1 ttl=64 time=0.164 ms 64 bytes from pcmk-1.clusterlabs.org (192.168.122.101): icmp_seq=2 ttl=64 time=0.475 ms 64 bytes from pcmk-1.clusterlabs.org (192.168.122.101): icmp_seq=3 ttl=64 time=0.186 ms --- pcmk-2.clusterlabs.org ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2001ms rtt min/avg/max/mdev = 0.164/0.275/0.475/0.141 ms ---- === Configure SSH === SSH is a convenient and secure way to copy files and perform commands remotely. For the purposes of this guide, we will create a key without a password (using the -N option) so that we can perform remote actions without being prompted. (((SSH))) [WARNING] ========= Unprotected SSH keys (those without a password) are not recommended for servers exposed to the outside world. We use them here only to simplify the demo. ========= Create a new key and allow anyone with that key to log in: .Creating and Activating a new SSH Key ---- [root@pcmk-1 ~]# ssh-keygen -t dsa -f ~/.ssh/id_dsa -N "" Generating public/private dsa key pair. Your identification has been saved in /root/.ssh/id_dsa. Your public key has been saved in /root/.ssh/id_dsa.pub. The key fingerprint is: 91:09:5c:82:5a:6a:50:08:4e:b2:0c:62:de:cc:74:44 root@pcmk-1.clusterlabs.org The key's randomart image is: +--[ DSA 1024]----+ |==.ooEo.. | |X O + .o o | | * A + | | + . | | . S | | | | | | | | | +-----------------+ [root@pcmk-1 ~]# cp ~/.ssh/id_dsa.pub ~/.ssh/authorized_keys ---- (((Creating and Activating a new SSH Key))) Install the key on the other node: ---- [root@pcmk-1 ~]# scp -r ~/.ssh pcmk-2: The authenticity of host 'pcmk-2 (192.168.122.102)' can't be established. ECDSA key fingerprint is a4:f5:b2:34:9d:86:2b:34:a2:87:37:b9:ca:68:52:ec. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'pcmk-2,192.168.122.102' (ECDSA) to the list of known hosts. root@pcmk-2's password: id_dsa.pub 100% 616 0.6KB/s 00:00 id_dsa 100% 672 0.7KB/s 00:00 known_hosts 100% 400 0.4KB/s 00:00 authorized_keys 100% 616 0.6KB/s 00:00 ---- Test that you can now run commands remotely, without being prompted: ---- [root@pcmk-1 ~]# ssh pcmk-2 -- uname -n pcmk-2 ---- == Install the Cluster Software == Fire up a shell on both nodes and run the following to install pacemaker, and while we're at it, some command-line tools to make our lives easier: ---- # yum install -y pacemaker pcs psmisc policycoreutils-python ---- [IMPORTANT] =========== This document will show commands that need to be executed on both nodes with a simple `#` prompt. Be sure to run them on each node individually. =========== [NOTE] =========== This document uses `pcs` for cluster management. Other alternatives, such as `crmsh`, are available, but their syntax will differ from the examples used here. =========== == Configure the Cluster Software == === Allow cluster services through firewall === On each node, allow cluster-related services through the local firewall: ---- # firewall-cmd --permanent --add-service=high-availability success # firewall-cmd --reload success ---- [NOTE] ====== If you are using iptables directly, or some other firewall solution besides firewalld, simply open the following ports, which can be used by various clustering components: TCP ports 2224, 3121, and 21064, and UDP port 5405. If you run into any problems during testing, you might want to disable the firewall and SELinux entirely until you have everything working. This may create significant security issues and should not be performed on machines that will be exposed to the outside world, but may be appropriate during development and testing on a protected host. To disable security measures: ---- [root@pcmk-1 ~]# setenforce 0 [root@pcmk-1 ~]# sed -i.bak "s/SELINUX=enforcing/SELINUX=permissive/g" /etc/selinux/config -[root@pcmk-1 ~]# systemctl disable firewalld.service +[root@pcmk-1 ~]# systemctl mask firewalld.service [root@pcmk-1 ~]# systemctl stop firewalld.service [root@pcmk-1 ~]# iptables --flush ---- ====== === Enable pcs Daemon === Before the cluster can be configured, the pcs daemon must be started and enabled to start at boot time on each node. This daemon works with the pcs command-line interface to manage synchronizing the corosync configuration across all nodes in the cluster. Start and enable the daemon by issuing the following commands on each node: ---- # systemctl start pcsd.service # systemctl enable pcsd.service ln -s '/usr/lib/systemd/system/pcsd.service' '/etc/systemd/system/multi-user.target.wants/pcsd.service' ---- The installed packages will create a *hacluster* user with a disabled password. While this is fine for running `pcs` commands locally, the account needs a login password in order to perform such tasks as syncing the corosync configuration, or starting and stopping the cluster on other nodes. This tutorial will make use of such commands, so now we will set a password for the *hacluster* user, using the same password on both nodes: ---- # passwd hacluster Changing password for user hacluster. New password: Retype new password: passwd: all authentication tokens updated successfully. ---- [NOTE] =========== Alternatively, to script this process or set the password on a different machine from the one you're logged into, you can use the `--stdin` option for `passwd`: ---- [root@pcmk-1 ~]# ssh pcmk-2 -- 'echo redhat1 | passwd --stdin hacluster' ---- =========== === Configure Corosync === On either node, use `pcs cluster auth` to authenticate as the *hacluster* user: ---- [root@pcmk-1 ~]# pcs cluster auth pcmk-1 pcmk-2 Username: hacluster Password: pcmk-1: Authorized pcmk-2: Authorized ---- Next, use `pcs cluster setup` on the same node to generate and synchronize the corosync configuration: ---- [root@pcmk-1 ~]# pcs cluster setup --name mycluster pcmk-1 pcmk-2 Shutting down pacemaker/corosync services... Redirecting to /bin/systemctl stop pacemaker.service Redirecting to /bin/systemctl stop corosync.service Killing any remaining services... Removing all cluster configuration files... pcmk-1: Succeeded pcmk-2: Succeeded ---- If you received an authorization error for either of those commands, make sure you configured the *hacluster* user account on each node with the same password. [NOTE] ====== Early versions of pcs required that `--name` be omitted from the above command. If you are not using `pcs` for cluster administration, follow whatever procedures are appropriate for your tools to create a corosync.conf and copy it to all nodes. The `pcs` command will configure corosync to use UDP unicast transport; if you choose to use multicast instead, choose a multicast address carefully. footnote:[For some subtle issues, see the now-defunct http://web.archive.org/web/20101211210054/http://29west.com/docs/THPM/multicast-address-assignment.html or the more detailed treatment in http://www.cisco.com/c/dam/en/us/support/docs/ip/ip-multicast/ipmlt_wp.pdf[Cisco's Guidelines for Enterprise IP Multicast Address Allocation] paper.] ====== The final /etc/corosync.conf configuration on each node should look something like the sample in <>. diff --git a/doc/Pacemaker_Remote/en-US/Ch-Baremetal-Tutorial.txt b/doc/Pacemaker_Remote/en-US/Ch-Baremetal-Tutorial.txt index f866c9a944..75f8d2216f 100644 --- a/doc/Pacemaker_Remote/en-US/Ch-Baremetal-Tutorial.txt +++ b/doc/Pacemaker_Remote/en-US/Ch-Baremetal-Tutorial.txt @@ -1,310 +1,310 @@ = Remote Node Walk-through = *What this tutorial is:* An in-depth walk-through of how to get Pacemaker to integrate a remote node into the cluster as a node capable of running cluster resources. *What 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 to act as cluster nodes, and a third to act as the remote node. == Configure Remote Node == === Configure Firewall on Remote Node === Allow cluster-related services through the local firewall: ---- # firewall-cmd --permanent --add-service=high-availability success # firewall-cmd --reload success ---- [NOTE] ====== If you are using iptables directly, or some other firewall solution besides firewalld, simply open the following ports, which can be used by various clustering components: TCP ports 2224, 3121, and 21064, and UDP port 5405. If you run into any problems during testing, you might want to disable the firewall and SELinux entirely until you have everything working. This may create significant security issues and should not be performed on machines that will be exposed to the outside world, but may be appropriate during development and testing on a protected host. To disable security measures: ---- # setenforce 0 # sed -i.bak "s/SELINUX=enforcing/SELINUX=permissive/g" /etc/selinux/config -# systemctl disable firewalld.service +# systemctl mask firewalld.service # systemctl stop firewalld.service # iptables --flush ---- ====== === Configure pacemaker_remote on Remote Node === Install the pacemaker_remote daemon on the remote node. ---- # yum install -y pacemaker-remote resource-agents pcs ---- Create a location for the shared authentication key: ---- # mkdir -p --mode=0750 /etc/pacemaker # chgrp haclient /etc/pacemaker ---- All nodes (both cluster nodes and remote nodes) must have the same authentication key installed for the communication to work correctly. If you already have a key on an existing node, copy it to the new remote node. Otherwise, create a new key, for example: ---- # dd if=/dev/urandom of=/etc/pacemaker/authkey bs=4096 count=1 ---- Now start and enable the pacemaker_remote daemon on the remote node. ---- # systemctl enable pacemaker_remote.service # systemctl start pacemaker_remote.service ---- Verify the start is successful. ---- # systemctl status pacemaker_remote pacemaker_remote.service - Pacemaker Remote Service Loaded: loaded (/usr/lib/systemd/system/pacemaker_remote.service; enabled) Active: active (running) since Fri 2015-08-21 15:21:20 CDT; 20s ago Main PID: 21273 (pacemaker_remot) CGroup: /system.slice/pacemaker_remote.service └─21273 /usr/sbin/pacemaker_remoted Aug 21 15:21:20 remote1 systemd[1]: Starting Pacemaker Remote Service... Aug 21 15:21:20 remote1 systemd[1]: Started Pacemaker Remote Service. Aug 21 15:21:20 remote1 pacemaker_remoted[21273]: notice: crm_add_logfile: Additional logging available in /var/log/pacemaker.log Aug 21 15:21:20 remote1 pacemaker_remoted[21273]: notice: lrmd_init_remote_tls_server: Starting a tls listener on port 3121. Aug 21 15:21:20 remote1 pacemaker_remoted[21273]: notice: bind_and_listen: Listening on address :: ---- == Verify Connection to Remote Node == Before moving forward, it's worth verifying that the cluster nodes can contact the remote node on port 3121. Here's a trick you can use. Connect using ssh 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 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 set up 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 remote node. ---- # cat << END >> /etc/hosts 192.168.122.10 remote1 END ---- If running the ssh command on one of the cluster nodes results in this output before disconnecting, the connection works: ---- # ssh -p 3121 remote1 ssh_exchange_identification: read: Connection reset by peer ---- If you see one of these, the connection is not working: ---- # ssh -p 3121 remote1 ssh: connect to host remote1 port 3121: No route to host ---- ---- # ssh -p 3121 remote1 ssh: connect to host remote1 port 3121: Connection refused ---- Once you can successfully connect to the remote node from the both cluster nodes, move on to setting up Pacemaker on the cluster nodes. == Configure Cluster Nodes == === Configure Firewall on Cluster Nodes === On each cluster node, allow cluster-related services through the local firewall, following the same procedure as in <<_configure_firewall_on_remote_node>>. === Install Pacemaker on Cluster Nodes === On the two cluster nodes, install the following packages. ---- # yum install -y pacemaker corosync pcs resource-agents ---- === Copy Authentication Key to Cluster Nodes === Create a location for the shared authentication key, and copy it from any existing node: ---- # mkdir -p --mode=0750 /etc/pacemaker # chgrp haclient /etc/pacemaker # scp remote1:/etc/pacemaker/authkey /etc/pacemaker/authkey ---- === Configure 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. ---- # pcs cluster setup --force --local --name mycluster ---- === Start Pacemaker on Cluster Nodes === Start the cluster stack on both cluster nodes using the following command. ---- # pcs cluster start ---- Verify corosync membership .... # pcs status corosync Membership information ---------------------- Nodeid Votes Name 1 1 node1 (local) .... Verify Pacemaker status. At first, the `pcs cluster status` output will look like this. ---- # pcs status Cluster name: mycluster Last updated: Fri Aug 21 16:14:05 2015 Last change: Fri Aug 21 14:02:14 2015 Stack: corosync Current DC: NONE Version: 1.1.12-a14efad 1 Nodes configured, unknown expected votes 0 Resources configured ---- After about a minute, you should see your two cluster nodes come online. ---- # pcs status Cluster name: mycluster Last updated: Fri Aug 21 16:16:32 2015 Last change: Fri Aug 21 14:02:14 2015 Stack: corosync Current DC: node1 (1) - partition with quorum Version: 1.1.12-a14efad 2 Nodes configured 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. ---- # pcs property set stonith-enabled=false ---- == Integrate Remote Node into Cluster == Integrating a 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 remote node, *remote1*, using the following command on any cluster node. ---- # pcs resource create remote1 ocf:pacemaker:remote ---- That's it. After a moment you should see the remote node come online. ---- Cluster name: mycluster Last updated: Fri Aug 21 17:13:09 2015 Last change: Fri Aug 21 17:02:02 2015 Stack: corosync Current DC: node1 (1) - partition with quorum Version: 1.1.12-a14efad 3 Nodes configured 1 Resources configured Online: [ node1 node2 ] RemoteOnline: [ remote1 ] Full list of resources: remote1 (ocf::pacemaker:remote): Started node1 PCSD Status: node1: Online node2: Online Daemon Status: corosync: active/disabled pacemaker: active/disabled pcsd: active/enabled ---- == Starting Resources on Remote Node == Once the remote node is integrated into the cluster, starting resources on a remote node is the exact same as on cluster nodes. Refer to the http://clusterlabs.org/doc/['Clusters from Scratch'] document for examples of resource creation. [WARNING] ========= Never involve a remote node connection resource in a resource group, colocation constraint, or order constraint. ========= == Fencing Remote Nodes == Remote nodes are fenced the same way as cluster nodes. No special considerations are required. Configure fencing resources for use with remote nodes the same as you would with cluster nodes. Note, however, that remote nodes can never 'initiate' a fencing action. Only cluster nodes are capable of actually executing a fencing operation against another node. == Accessing Cluster Tools from a 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`, etc.) to work on remote nodes natively. Try it: Run `crm_mon` on the remote node after pacemaker has integrated it 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. Higher-level command shells such as `pcs` may have partial support on remote nodes, but it is recommended to run them from a cluster node. diff --git a/doc/Pacemaker_Remote/en-US/Ch-KVM-Tutorial.txt b/doc/Pacemaker_Remote/en-US/Ch-KVM-Tutorial.txt index 7f09598e31..2c38d5ed10 100644 --- a/doc/Pacemaker_Remote/en-US/Ch-KVM-Tutorial.txt +++ b/doc/Pacemaker_Remote/en-US/Ch-KVM-Tutorial.txt @@ -1,583 +1,583 @@ = Guest Node Walk-through = *What 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 guest node. *What this tutorial is not:* A realistic deployment scenario. The steps shown here are meant to get users familiar with the concept of guest nodes as quickly as possible. == Configure the Physical Host == [NOTE] ====== For this example, we will use a single physical host named *example-host*. A production cluster would likely have multiple physical hosts, in which case you would run the commands here on each one, unless noted otherwise. ====== === Configure Firewall on Host === On the physical host, allow cluster-related services through the local firewall: ---- # firewall-cmd --permanent --add-service=high-availability success # firewall-cmd --reload success ---- [NOTE] ====== If you are using iptables directly, or some other firewall solution besides firewalld, simply open the following ports, which can be used by various clustering components: TCP ports 2224, 3121, and 21064, and UDP port 5405. If you run into any problems during testing, you might want to disable the firewall and SELinux entirely until you have everything working. This may create significant security issues and should not be performed on machines that will be exposed to the outside world, but may be appropriate during development and testing on a protected host. To disable security measures: ---- [root@pcmk-1 ~]# setenforce 0 [root@pcmk-1 ~]# sed -i.bak "s/SELINUX=enforcing/SELINUX=permissive/g" /etc/selinux/config -[root@pcmk-1 ~]# systemctl disable firewalld.service +[root@pcmk-1 ~]# systemctl mask firewalld.service [root@pcmk-1 ~]# systemctl stop firewalld.service [root@pcmk-1 ~]# iptables --flush ---- ====== === Install Cluster Software === ---- # yum install -y pacemaker corosync pcs resource-agents ---- === Configure 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, replacing the cluster name and hostname as desired: ---- # pcs cluster setup --force --local --name mycluster example-host ---- [NOTE] ====== If you have multiple physical hosts, you would execute the setup command on only one host, but list all of them at the end of the command. ====== === Configure Pacemaker for Remote Node Communication === Create a place to hold an authentication key for use with pacemaker_remote: ---- # mkdir -p --mode=0750 /etc/pacemaker # chgrp haclient /etc/pacemaker ---- Generate a key: ---- # dd if=/dev/urandom of=/etc/pacemaker/authkey bs=4096 count=1 ---- [NOTE] ====== If you have multiple physical hosts, you would generate the key on only one host, and copy it to the same location on all hosts. ====== === Verify Cluster Software === Start the cluster ---- # pcs cluster start ---- Verify corosync membership .... # pcs status corosync Membership information ---------------------- Nodeid Votes Name 1 1 example-host (local) .... Verify pacemaker status. At first, the output will look like this: ---- # pcs status Cluster name: mycluster WARNING: no stonith devices and stonith-enabled is not false Last updated: Fri Oct 9 15:18:32 2015 Last change: Fri Oct 9 12:42:21 2015 by root via cibadmin on example-host Stack: corosync Current DC: NONE 1 node and 0 resources configured Node example-host: UNCLEAN (offline) Full list of resources: PCSD Status: example-host: Online Daemon Status: corosync: active/disabled pacemaker: active/disabled pcsd: active/enabled ---- After a short amount of time, you should see your host as a single node in the cluster: ---- # pcs status Cluster name: mycluster WARNING: no stonith devices and stonith-enabled is not false Last updated: Fri Oct 9 15:20:05 2015 Last change: Fri Oct 9 12:42:21 2015 by root via cibadmin on example-host Stack: corosync Current DC: example-host (version 1.1.13-a14efad) - partition WITHOUT quorum 1 node and 0 resources configured Online: [ example-host ] Full list of resources: PCSD Status: example-host: Online Daemon Status: corosync: active/disabled pacemaker: active/disabled pcsd: active/enabled ---- === Disable STONITH and Quorum === Now, enable the cluster to work without quorum or stonith. This is required for the sake of getting this tutorial to work with a single cluster node. ---- # pcs property set stonith-enabled=false # pcs property set no-quorum-policy=ignore ---- [WARNING] ========= The use of `stonith-enabled=false` is completely inappropriate for a production cluster. It tells the cluster to simply pretend that failed nodes are safely powered off. Some vendors will refuse to support clusters that have STONITH disabled. We disable STONITH here only to focus the discussion on pacemaker_remote, and to be able to use a single physical host in the example. ========= Now, the status output should look similar to this: ---- # pcs status Cluster name: mycluster Last updated: Fri Oct 9 15:22:49 2015 Last change: Fri Oct 9 15:22:46 2015 by root via cibadmin on example-host Stack: corosync Current DC: example-host (version 1.1.13-a14efad) - partition with quorum 1 node and 0 resources configured Online: [ example-host ] Full list of resources: PCSD Status: example-host: Online Daemon Status: corosync: active/disabled pacemaker: active/disabled pcsd: active/enabled ---- Go ahead and stop the cluster for now after verifying everything is in order. ---- # pcs cluster stop --force ---- === Install Virtualization Software === ---- # yum install -y kvm libvirt qemu-system qemu-kvm bridge-utils virt-manager # systemctl enable libvirtd.service ---- Reboot the host. [NOTE] ====== While KVM is used in this example, any virtualization platform with a Pacemaker resource agent can be used to create a guest node. The resource agent needs only to support usual commands (start, stop, etc.); Pacemaker implements the *remote-node* meta-attribute, independent of the agent. ====== == Configure the KVM guest == === Create Guest === We will not outline here the installation steps required to create a KVM guest. There are plenty of tutorials available elsewhere that do that. Just be sure to configure the guest with a hostname and a static IP address (as an example here, we will use guest1 and 192.168.122.10). === Configure Firewall on Guest === On each guest, allow cluster-related services through the local firewall, following the same procedure as in <<_configure_firewall_on_host>>. === Verify Connectivity === At this point, you should be able to ping and ssh into guests from hosts, and vice versa. === Configure pacemaker_remote === Install pacemaker_remote, and enable it to run at start-up. Here, we also install the pacemaker package; it is not required, but it contains the dummy resource agent that we will use later for testing. ---- # yum install -y pacemaker pacemaker-remote resource-agents # systemctl enable pacemaker_remote.service ---- Copy the authentication key from a host: ---- # mkdir -p --mode=0750 /etc/pacemaker # chgrp haclient /etc/pacemaker # scp root@example-host:/etc/pacemaker/authkey /etc/pacemaker ---- Start pacemaker_remote, and verify the start was successful: ---- # systemctl start pacemaker_remote # 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 verifying that the host can contact the guest on port 3121. Here's a trick you can use. Connect using ssh 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. ---- # cat << END >> /etc/hosts 192.168.122.10 guest1 END ---- If running the ssh command on one of the cluster nodes results in this output before disconnecting, the connection works: ---- # ssh -p 3121 guest1 ssh_exchange_identification: read: Connection reset by peer ---- If you see one of these, the connection is not working: ---- # ssh -p 3121 guest1 ssh: connect to host guest1 port 3121: No route to host ---- ---- # ssh -p 3121 guest1 ssh: connect to host guest1 port 3121: Connection refused ---- 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. == Integrate 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. ---- # pcs cluster start ---- Wait for the host to become the DC. The output of `pcs status` should look as it did in <<_disable_stonith_and_quorum>>. === Integrate as Guest Node === If you didn't already do this earlier in the verify host to guest connection section, add the KVM guest's IP address to the host's +/etc/hosts+ file so we can connect by hostname. For this example: ---- # 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. .... # 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. ---- # virsh dumpxml guest1 > /etc/pacemaker/guest1.xml ---- Now just register the resource with pacemaker and you're set! ---- # pcs resource create vm-guest1 VirtualDomain hypervisor="qemu:///system" \ config="/etc/pacemaker/guest1.xml" meta remote-node=guest1 ---- [NOTE] ====== This example puts the guest XML under /etc/pacemaker because the permissions and SELinux labeling should not need any changes. If you run into trouble with this or any step, try disabling SELinux with `setenforce 0`. If it works after that, see SELinux documentation for how to troubleshoot, if you wish to reenable SELinux. ====== [NOTE] ====== Pacemaker will automatically monitor pacemaker_remote connections for failure, so it is not necessary to create a recurring monitor on the VirtualDomain resource. ====== 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. ---- # pcs status Cluster name: mycluster Last updated: Fri Oct 9 18:00:45 2015 Last change: Fri Oct 9 17:53:44 2015 by root via crm_resource on example-host Stack: corosync Current DC: example-host (version 1.1.13-a14efad) - partition with quorum 2 nodes and 2 resources configured Online: [ example-host ] GuestOnline: [ guest1@example-host ] Full list of resources: vm-guest1 (ocf::heartbeat:VirtualDomain): Started example-host PCSD Status: example-host: Online Daemon Status: corosync: active/disabled pacemaker: active/disabled pcsd: active/enabled ---- === Starting Resources on KVM Guest === The commands below demonstrate how resources can be executed on both the guest 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. ---- # 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 started on the cluster node, and some started on the guest node. ---- 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 guest 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. ---- # pcs constraint location FAKE3 prefers guest1 ---- Now, looking at the bottom of the `pcs status` output you'll see FAKE3 is on *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 ---- === Testing Recovery and Fencing === Pacemaker's policy engine is smart enough to know fencing guest 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. ---- # kill -9 `pidof pacemaker_remoted` ---- Within a few seconds, your `pcs status` output will show a monitor failure, and the *guest1* node will not be shown while it is being recovered. ---- # pcs status Cluster name: mycluster Last updated: Fri Oct 9 18:08:35 2015 Last change: Fri Oct 9 18:07:00 2015 by root via cibadmin on example-host Stack: corosync Current DC: example-host (version 1.1.13-a14efad) - partition with quorum 2 nodes and 7 resources configured Online: [ example-host ] 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 on example-host 'unknown error' (1): call=8, status=Error, exitreason='none', last-rc-change='Fri Oct 9 18:08:29 2015', queued=0ms, exec=0ms PCSD Status: example-host: Online Daemon Status: corosync: active/disabled pacemaker: active/disabled pcsd: active/enabled ---- [NOTE] ====== A guest node involves two resources: the one you explicitly configured creates the guest, and Pacemaker creates an implicit resource for the pacemaker_remote connection, which will be named the same as the value of the *remote-node* attribute of the explicit resource. When we killed pacemaker_remote, it is the implicit resource that failed, which is why the failed action starts with *guest1* and not *vm-guest1*. ====== 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. ---- Cluster name: mycluster Last updated: Fri Oct 9 18:18:30 2015 Last change: Fri Oct 9 18:07:00 2015 by root via cibadmin on example-host Stack: corosync Current DC: example-host (version 1.1.13-a14efad) - partition with quorum 2 nodes and 7 resources configured Online: [ example-host ] GuestOnline: [ guest1@example-host ] 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 on example-host 'unknown error' (1): call=8, status=Error, exitreason='none', last-rc-change='Fri Oct 9 18:08:29 2015', queued=0ms, exec=0ms PCSD Status: example-host: Online Daemon Status: corosync: active/disabled pacemaker: active/disabled pcsd: active/enabled ---- Normally, once you've investigated and addressed a failed action, you can clear the failure. However Pacemaker does not yet support cleanup for the implicitly created connection resource while the explicit resource is active. If you want to clear the failed action from the status output, stop the guest resource before clearing it. For example: ---- # pcs resource disable vm-guest1 --wait # pcs resource cleanup guest1 # pcs resource enable vm-guest1 ---- === Accessing Cluster Tools from Guest Node === Besides allowing the cluster to manage resources on a guest 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`, etc.) to work on guest nodes natively. Try it: Run `crm_mon` on the guest after pacemaker has integrated the guest node into the cluster. These tools just work. This means resource agents such as master/slave resources which need access to tools like `crm_master` work seamlessly on the guest nodes. Higher-level command shells such as `pcs` may have partial support on guest nodes, but it is recommended to run them from a cluster node.