diff --git a/doc/Clusters_from_Scratch/en-US/Ch-Active-Passive.txt b/doc/Clusters_from_Scratch/en-US/Ch-Active-Passive.txt index 0cd3463113..f75cb34e2b 100644 --- a/doc/Clusters_from_Scratch/en-US/Ch-Active-Passive.txt +++ b/doc/Clusters_from_Scratch/en-US/Ch-Active-Passive.txt @@ -1,377 +1,268 @@ :compat-mode: legacy = Create an Active/Passive Cluster = -== Explore the Existing Configuration == - -When Pacemaker starts up, it automatically records the number and details -of the nodes in the cluster, as well as which stack is being used and the -version of Pacemaker being used. - -The first few lines of output should look like this: - ----- -[root@pcmk-1 ~]# pcs status -Cluster name: mycluster -WARNING: no stonith devices and stonith-enabled is not false -Stack: corosync -Current DC: pcmk-2 (version 1.1.18-11.el7_5.3-2b07d5c5a9) - partition with quorum -Last updated: Mon Sep 10 16:41:46 2018 -Last change: Mon Sep 10 16:30:53 2018 by hacluster via crmd on pcmk-2 - -2 nodes configured -0 resources configured - -Online: [ pcmk-1 pcmk-2 ] ----- - -For those who are not of afraid of XML, you can see the raw cluster -configuration and status by using the `pcs cluster cib` command. - -.The last XML you'll see in this document -====== ----- -[root@pcmk-1 ~]# pcs cluster cib ----- -[source,XML] ----- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ----- -====== - -Before we make any changes, it's a good idea to check the validity of -the configuration. - ----- -[root@pcmk-1 ~]# crm_verify -L -V - error: unpack_resources: Resource start-up disabled since no STONITH resources have been defined - error: unpack_resources: Either configure some or disable STONITH with the stonith-enabled option - error: unpack_resources: NOTE: Clusters with shared data need STONITH to ensure data integrity -Errors found during check: config not valid ----- - -As you can see, the tool has found some errors. - -In order to guarantee the safety of your data, -footnote:[If the data is corrupt, there is little point in continuing to make it available] -fencing (also called STONITH) is enabled by default. However, it also knows -when no STONITH configuration has been supplied and reports this as a problem -(since the cluster will not be able to make progress if a situation requiring -node fencing arises). - -We will disable this feature for now and configure it later. - -To disable STONITH, set the *stonith-enabled* cluster option to -false: - ----- -[root@pcmk-1 ~]# pcs property set stonith-enabled=false -[root@pcmk-1 ~]# crm_verify -L ----- - -With the new cluster option set, the configuration is now valid. - -[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 defer the discussion of its -configuration, which can differ widely from one installation to the -next. See <<_what_is_stonith>> for information on why STONITH is important -and details on how to configure it. -========= - == Add a Resource == Our first resource will be a unique IP address that the cluster can bring up on either node. Regardless of where any cluster service(s) are running, end users need a consistent address to contact them on. Here, I will choose 192.168.122.120 as the floating address, give it the imaginative name ClusterIP and tell the cluster to check whether it is running every 30 seconds. [WARNING] =========== The chosen address must not already be in use on the network. Do not reuse an IP address one of the nodes already has configured. =========== ---- [root@pcmk-1 ~]# pcs resource create ClusterIP ocf:heartbeat:IPaddr2 \ ip=192.168.122.120 cidr_netmask=24 op monitor interval=30s ---- Another important piece of information here is *ocf:heartbeat:IPaddr2*. This tells Pacemaker three things about the resource you want to add: * The first field (*ocf* in this case) is the standard to which the resource script conforms and where to find it. * The second field (*heartbeat* in this case) is standard-specific; for OCF resources, it tells the cluster which OCF namespace the resource script is in. * The third field (*IPaddr2* in this case) is the name of the resource script. To obtain a list of the available resource standards (the *ocf* part of *ocf:heartbeat:IPaddr2*), run: ---- [root@pcmk-1 ~]# pcs resource standards lsb ocf service systemd ---- To obtain a list of the available OCF resource providers (the *heartbeat* part of *ocf:heartbeat:IPaddr2*), run: ---- [root@pcmk-1 ~]# pcs resource providers heartbeat openstack pacemaker ---- Finally, if you want to see all the resource agents available for a specific OCF provider (the *IPaddr2* part of *ocf:heartbeat:IPaddr2*), run: ---- [root@pcmk-1 ~]# pcs resource agents ocf:heartbeat apache aws-vpc-move-ip awseip awsvip azure-lb clvm . . (skipping lots of resources to save space) . symlink tomcat VirtualDomain Xinetd ---- Now, verify that the IP resource has been added, and display the cluster's status to see that it is now active: ---- [root@pcmk-1 ~]# pcs status Cluster name: mycluster Stack: corosync Current DC: pcmk-2 (version 1.1.18-11.el7_5.3-2b07d5c5a9) - partition with quorum Last updated: Mon Sep 10 16:55:26 2018 Last change: Mon Sep 10 16:53:42 2018 by root via cibadmin on pcmk-1 2 nodes configured 1 resource configured Online: [ pcmk-1 pcmk-2 ] Full list of resources: ClusterIP (ocf::heartbeat:IPaddr2): Started pcmk-1 Daemon Status: corosync: active/disabled pacemaker: active/disabled pcsd: active/enabled ---- == Perform a Failover == Since our ultimate goal is high availability, we should test failover of our new resource before moving on. First, find the node on which the IP address is running. ---- [root@pcmk-1 ~]# pcs status Cluster name: mycluster Stack: corosync Current DC: pcmk-2 (version 1.1.18-11.el7_5.3-2b07d5c5a9) - partition with quorum Last updated: Mon Sep 10 16:55:26 2018 Last change: Mon Sep 10 16:53:42 2018 by root via cibadmin on pcmk-1 2 nodes configured 1 resource configured Online: [ pcmk-1 pcmk-2 ] Full list of resources: ClusterIP (ocf::heartbeat:IPaddr2): Started pcmk-1 ---- You can see that the status of the *ClusterIP* resource is *Started* on a particular node (in this example, *pcmk-1*). Shut down Pacemaker and Corosync on that machine to trigger a failover. ---- [root@pcmk-1 ~]# pcs cluster stop pcmk-1 Stopping Cluster (pacemaker)... Stopping Cluster (corosync)... ---- [NOTE] ====== A cluster command such as +pcs cluster stop pass:[nodename]+ can be run from any node in the cluster, not just the affected node. ====== Verify that pacemaker and corosync are no longer running: ---- [root@pcmk-1 ~]# pcs status Error: cluster is not currently running on this node ---- Go to the other node, and check the cluster status. ---- [root@pcmk-2 ~]# pcs status Cluster name: mycluster Stack: corosync Current DC: pcmk-2 (version 1.1.18-11.el7_5.3-2b07d5c5a9) - partition with quorum Last updated: Mon Sep 10 16:57:22 2018 Last change: Mon Sep 10 16:53:42 2018 by root via cibadmin on pcmk-1 2 nodes configured 1 resource configured Online: [ pcmk-2 ] OFFLINE: [ pcmk-1 ] Full list of resources: ClusterIP (ocf::heartbeat:IPaddr2): Started pcmk-2 Daemon Status: corosync: active/disabled pacemaker: active/disabled pcsd: active/enabled ---- Notice that *pcmk-1* is *OFFLINE* for cluster purposes (its *pcsd* is still active, allowing it to receive `pcs` commands, but it is not participating in the cluster). Also notice that *ClusterIP* is now running on *pcmk-2* -- failover happened automatically, and no errors are reported. [IMPORTANT] .Quorum ==== If a cluster splits into two (or more) groups of nodes that can no longer communicate with each other (aka. _partitions_), _quorum_ is used to prevent resources from starting on more nodes than desired, which would risk data corruption. A cluster has quorum when more than half of all known nodes are online in the same partition, or for the mathematically inclined, whenever the following equation is true: .... total_nodes < 2 * active_nodes .... For example, if a 5-node cluster split into 3- and 2-node paritions, the 3-node partition would have quorum and could continue serving resources. If a 6-node cluster split into two 3-node partitions, neither partition would have quorum; pacemaker's default behavior in such cases is to stop all resources, in order to prevent data corruption. Two-node clusters are a special case. By the above definition, a two-node cluster would only have quorum when both nodes are running. This would make the creation of a two-node cluster pointless, but corosync has the ability to treat two-node clusters as if only one node is required for quorum. The `pcs cluster setup` command will automatically configure *two_node: 1* in +corosync.conf+, so a two-node cluster will "just work". If you are using a different cluster shell, you will have to configure +corosync.conf+ appropriately yourself. ==== Now, simulate node recovery by restarting the cluster stack on *pcmk-1*, and check the cluster's status. (It may take a little while before the cluster gets going on the node, but it eventually will look like the below.) ---- [root@pcmk-1 ~]# pcs cluster start pcmk-1 pcmk-1: Starting Cluster... [root@pcmk-1 ~]# pcs status Cluster name: mycluster Stack: corosync Current DC: pcmk-2 (version 1.1.18-11.el7_5.3-2b07d5c5a9) - partition with quorum Last updated: Mon Sep 10 17:00:04 2018 Last change: Mon Sep 10 16:53:42 2018 by root via cibadmin on pcmk-1 2 nodes configured 1 resource configured Online: [ pcmk-1 pcmk-2 ] Full list of resources: ClusterIP (ocf::heartbeat:IPaddr2): Started pcmk-2 Daemon Status: corosync: active/disabled pacemaker: active/disabled pcsd: active/enabled ---- == Prevent Resources from Moving after Recovery == In most circumstances, it is highly desirable to prevent healthy resources from being moved around the cluster. Moving resources almost always requires a period of downtime. For complex services such as databases, this period can be quite long. To address this, Pacemaker has the concept of resource _stickiness_, which controls how strongly a service prefers to stay running where it is. You may like to think of it as the "cost" of any downtime. By default, Pacemaker assumes there is zero cost associated with moving resources and will do so to achieve "optimal" footnote:[Pacemaker's definition of optimal may not always agree with that of a human's. The order in which Pacemaker processes lists of resources and nodes creates implicit preferences in situations where the administrator has not explicitly specified them.] resource placement. We can specify a different stickiness for every resource, but it is often sufficient to change the default. ---- [root@pcmk-1 ~]# pcs resource defaults resource-stickiness=100 Warning: Defaults do not apply to resources which override them with their own defined values [root@pcmk-1 ~]# pcs resource defaults resource-stickiness: 100 ---- diff --git a/doc/Clusters_from_Scratch/en-US/Ch-Stonith.txt b/doc/Clusters_from_Scratch/en-US/Ch-Fencing.txt similarity index 66% rename from doc/Clusters_from_Scratch/en-US/Ch-Stonith.txt rename to doc/Clusters_from_Scratch/en-US/Ch-Fencing.txt index e25735440f..6987c69460 100644 --- a/doc/Clusters_from_Scratch/en-US/Ch-Stonith.txt +++ b/doc/Clusters_from_Scratch/en-US/Ch-Fencing.txt @@ -1,170 +1,210 @@ :compat-mode: legacy -= Configure STONITH = += Configure Fencing = -== What is STONITH? == +== What is Fencing? == -STONITH (Shoot The Other Node In The Head aka. fencing) protects your data from -being corrupted by rogue nodes or unintended concurrent access. +Fencing protects your data from being corrupted, and your application from +becoming unavailable, due to unintended concurrent access by rogue nodes. Just because a node is unresponsive doesn't mean it has stopped accessing your data. The only way to be 100% sure that your data is -safe, is to use STONITH to ensure that the node is truly +safe, is to use fencing to ensure that the node is truly offline before allowing the data to be accessed from another node. -STONITH also has a role to play in the event that a clustered service -cannot be stopped. In this case, the cluster uses STONITH to force the +Fencing also has a role to play in the event that a clustered service +cannot be stopped. In this case, the cluster uses fencing to force the whole node offline, thereby making it safe to start the service elsewhere. -== Choose a STONITH Device == +Fencing is also known as STONITH, an acronym for "Shoot The Other Node In The +Head", since the most popular form of fencing is cutting a host's power. -It is crucial that your STONITH device can allow the cluster to -differentiate between a node failure and a network failure. +In order to guarantee the safety of your data, +footnote:[If the data is corrupt, there is little point in continuing to make it available] +fencing is enabled by default. -A common mistake people make when choosing a STONITH device is to use a remote -power switch (such as many on-board IPMI controllers) that shares power with -the node it controls. If the power fails in such a case, the cluster cannot be -sure whether the node is really offline, or active and suffering from a network -fault, so the cluster will stop all resources to avoid a possible split-brain -situation. +[NOTE] +==== +It is possible to tell the cluster not to use fencing, by setting the +*stonith-enabled* cluster option to false: +---- +[root@pcmk-1 ~]# pcs property set stonith-enabled=false +[root@pcmk-1 ~]# crm_verify -L +---- + +However, this 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 fencing disabled. Even +disabling it for a test cluster means you won't be able to test real failure +scenarios. +==== + +== Choose a Fence Device == + +The two broad categories of fence device are power fencing, which cuts off +power to the target, and fabric fencing, which cuts off the target's access to +some critical resource, such as a shared disk or access to the local network. + +Power fencing devices include: + +* Intelligent power switches +* IPMI +* Hardware watchdog device (alone, or in combination with shared storage used + as a "poison pill" mechanism) + +Fabric fencing devices include: + +* Shared storage that can be cut off for a target host by another host (for + example, an external storage device that supports SCSI-3 persistent + reservations) +* Intelligent network switches + +Using IPMI as a power fencing device may seem like a good choice. However, +if the IPMI shares power and/or network access with the host (such as most +onboard IPMI controllers), a power or network failure will cause both the +host and its fencing device to fail. The cluster will be unable to recover, +and must stop all resources to avoid a possible split-brain situation. Likewise, any device that relies on the machine being active (such as -SSH-based "devices" sometimes used during testing) is inappropriate. +SSH-based "devices" sometimes used during testing) is inappropriate, +because fencing will be required when the node is completely unresponsive. -== Configure the Cluster for STONITH == +== Configure the Cluster for Fencing == -. Install the STONITH agent(s). To see what packages are available, run `yum +. Install the fence agent(s). To see what packages are available, run `yum search fence-`. Be sure to install the package(s) on all cluster nodes. -. Configure the STONITH device itself to be able to fence your nodes and accept +. Configure the fence device itself to be able to fence your nodes and accept fencing requests. This includes any necessary configuration on the device and on the nodes, and any firewall or SELinux changes needed. Test the communication between the device and your nodes. -. Find the correct STONITH agent script: `pcs stonith list` +. Find the name of the correct fence agent: `pcs stonith list` -. Find the parameters associated with the device: +pcs stonith describe pass:[agent_name]+ +. Find the parameters associated with the device: + +pcs stonith describe pass:[agent_name]+ . Create a local copy of the CIB: `pcs cluster cib stonith_cfg` . Create the fencing resource: +pcs -f stonith_cfg stonith create pass:[stonith_id stonith_device_type [stonith_device_options]]+ + Any flags that do not take arguments, such as +--ssl+, should be passed as +ssl=1+. -. Enable STONITH in the cluster: `pcs -f stonith_cfg property set stonith-enabled=true` +. Enable fencing in the cluster: `pcs -f stonith_cfg property set stonith-enabled=true` -. If the device does not know how to fence nodes based on their uname, - you may also need to set the special *pcmk_host_map* parameter. See +. If the device does not know how to fence nodes based on their cluster node + name, you may also need to set the special *pcmk_host_map* parameter. See `man pacemaker-fenced` for details. . If the device does not support the *list* command, you may also need to set the special *pcmk_host_list* and/or *pcmk_host_check* parameters. See `man pacemaker-fenced` for details. . If the device does not expect the victim to be specified with the *port* parameter, you may also need to set the special *pcmk_host_argument* parameter. See `man pacemaker-fenced` for details. . Commit the new configuration: `pcs cluster cib-push stonith_cfg` -. Once the STONITH resource is running, test it (you might want to stop - the cluster on that machine first): +stonith_admin --reboot pass:[nodename]+ +. Once the fence device resource is running, test it (you might want to stop + the cluster on that machine first): + +stonith_admin --reboot pass:[nodename]+ == Example == For this example, assume we have a chassis containing four nodes -and an IPMI device active on 10.0.0.1. Following the steps above -would go something like this: +and a separately powered IPMI device active on 10.0.0.1. Following the steps +above would go something like this: Step 1: Install the *fence-agents-ipmilan* package on both nodes. Step 2: Configure the IP address, authentication credentials, etc. in the IPMI device itself. Step 3: Choose the *fence_ipmilan* STONITH agent. Step 4: Obtain the agent's possible parameters: ---- [root@pcmk-1 ~]# pcs stonith describe fence_ipmilan fence_ipmilan - Fence agent for IPMI fence_ipmilan is an I/O Fencing agentwhich can be used with machines controlled by IPMI.This agent calls support software ipmitool (http://ipmitool.sf.net/). WARNING! This fence agent might report success before the node is powered off. You should use -m/method onoff if your fence device works correctly with that option. Stonith options: ipport: TCP/UDP port to use for connection with device hexadecimal_kg: Hexadecimal-encoded Kg key for IPMIv2 authentication port: IP address or hostname of fencing device (together with --port-as-ip) inet6_only: Forces agent to use IPv6 addresses only ipaddr: IP Address or Hostname passwd_script: Script to retrieve password method: Method to fence (onoff|cycle) inet4_only: Forces agent to use IPv4 addresses only passwd: Login password or passphrase lanplus: Use Lanplus to improve security of connection auth: IPMI Lan Auth type. cipher: Ciphersuite to use (same as ipmitool -C parameter) target: Bridge IPMI requests to the remote target address privlvl: Privilege level on IPMI device timeout: Timeout (sec) for IPMI operation login: Login Name verbose: Verbose mode debug: Write debug information to given file power_wait: Wait X seconds after issuing ON/OFF login_timeout: Wait X seconds for cmd prompt after login delay: Wait X seconds before fencing is started power_timeout: Test X seconds for status change after ON/OFF ipmitool_path: Path to ipmitool binary shell_timeout: Wait X seconds for cmd prompt after issuing command port_as_ip: Make "port/plug" to be an alias to IP address retry_on: Count of attempts to retry power on sudo: Use sudo (without password) when calling 3rd party sotfware. priority: The priority of the stonith resource. Devices are tried in order of highest priority to lowest. pcmk_host_map: A mapping of host names to ports numbers for devices that do not support host names. Eg. node1:1;node2:2,3 would tell the cluster to use port 1 for node1 and ports 2 and 3 for node2 pcmk_host_list: A list of machines controlled by this device (Optional unless pcmk_host_check=static-list). pcmk_host_check: How to determine which machines are controlled by the device. Allowed values: dynamic-list (query the device), static-list (check the pcmk_host_list attribute), none (assume every device can fence every machine) pcmk_delay_max: Enable a random delay for stonith actions and specify the maximum of random delay. This prevents double fencing when using slow devices such as sbd. Use this to enable a random delay for stonith actions. The overall delay is derived from this random delay value adding a static delay so that the sum is kept below the maximum delay. pcmk_delay_base: Enable a base delay for stonith actions and specify base delay value. This prevents double fencing when different delays are configured on the nodes. Use this to enable a static delay for stonith actions. The overall delay is derived from a random delay value adding this static delay so that the sum is kept below the maximum delay. pcmk_action_limit: The maximum number of actions can be performed in parallel on this device Pengine property concurrent-fencing=true needs to be configured first. Then use this to specify the maximum number of actions can be performed in parallel on this device. -1 is unlimited. Default operations: monitor: interval=60s ---- Step 5: `pcs cluster cib stonith_cfg` -Step 6: Here are example parameters for creating our STONITH resource: +Step 6: Here are example parameters for creating our fence device resource: ---- [root@pcmk-1 ~]# pcs -f stonith_cfg stonith create ipmi-fencing fence_ipmilan \ pcmk_host_list="pcmk-1 pcmk-2" ipaddr=10.0.0.1 login=testuser \ passwd=acd123 op monitor interval=60s [root@pcmk-1 ~]# pcs -f stonith_cfg stonith ipmi-fencing (stonith:fence_ipmilan): Stopped ---- -Steps 7-10: Enable STONITH in the cluster: +Steps 7-10: Enable fencing in the cluster: ---- [root@pcmk-1 ~]# pcs -f stonith_cfg property set stonith-enabled=true [root@pcmk-1 ~]# pcs -f stonith_cfg property Cluster Properties: cluster-infrastructure: corosync cluster-name: mycluster dc-version: 1.1.18-11.el7_5.3-2b07d5c5a9 have-watchdog: false stonith-enabled: true ---- Step 11: `pcs cluster cib-push stonith_cfg --config` Step 12: Test: ---- [root@pcmk-1 ~]# pcs cluster stop pcmk-2 [root@pcmk-1 ~]# stonith_admin --reboot pcmk-2 ---- After a successful test, login to any rebooted nodes, and start the cluster (with `pcs cluster start`). diff --git a/doc/Clusters_from_Scratch/en-US/Ch-Verification.txt b/doc/Clusters_from_Scratch/en-US/Ch-Verification.txt index d4762e34fa..e21688dbc0 100644 --- a/doc/Clusters_from_Scratch/en-US/Ch-Verification.txt +++ b/doc/Clusters_from_Scratch/en-US/Ch-Verification.txt @@ -1,151 +1,210 @@ :compat-mode: legacy = Start and Verify Cluster = == Start the Cluster == Now that corosync is configured, it is time to start the cluster. The command below will start corosync and pacemaker on both nodes in the cluster. If you are issuing the start command from a different node than the one you ran the `pcs cluster auth` command on earlier, you must authenticate on the current node you are logged into before you will be allowed to start the cluster. ---- [root@pcmk-1 ~]# pcs cluster start --all pcmk-1: Starting Cluster... pcmk-2: Starting Cluster... ---- [NOTE] ====== An alternative to using the `pcs cluster start --all` command is to issue either of the below command sequences on each node in the cluster separately: ---- # pcs cluster start Starting Cluster... ---- or ---- # systemctl start corosync.service # systemctl start pacemaker.service ---- ====== [IMPORTANT] ==== In this example, we are not enabling the corosync and pacemaker services to start at boot. If a cluster node fails or is rebooted, you will need to run +pcs cluster start pass:[nodename]+ (or `--all`) to start the cluster on it. While you could enable the services to start at boot, requiring a manual start of cluster services gives you the opportunity to do a post-mortem investigation of a node failure before returning it to the cluster. ==== == Verify Corosync Installation == First, use `corosync-cfgtool` to check whether cluster communication is happy: ---- [root@pcmk-1 ~]# corosync-cfgtool -s Printing ring status. Local node ID 1 RING ID 0 id = 192.168.122.101 status = ring 0 active with no faults ---- We can see here that everything appears normal with our fixed IP address (not a 127.0.0.x loopback address) listed as the *id*, and *no faults* for the status. If you see something different, you might want to start by checking the node's network, firewall and SELinux configurations. Next, check the membership and quorum APIs: ---- [root@pcmk-1 ~]# corosync-cmapctl | grep members runtime.totem.pg.mrp.srp.members.1.config_version (u64) = 0 runtime.totem.pg.mrp.srp.members.1.ip (str) = r(0) ip(192.168.122.101) runtime.totem.pg.mrp.srp.members.1.join_count (u32) = 1 runtime.totem.pg.mrp.srp.members.1.status (str) = joined runtime.totem.pg.mrp.srp.members.2.config_version (u64) = 0 runtime.totem.pg.mrp.srp.members.2.ip (str) = r(0) ip(192.168.122.102) runtime.totem.pg.mrp.srp.members.2.join_count (u32) = 1 runtime.totem.pg.mrp.srp.members.2.status (str) = joined [root@pcmk-1 ~]# pcs status corosync Membership information \---------------------- Nodeid Votes Name 1 1 pcmk-1 (local) 2 1 pcmk-2 ---- You should see both nodes have joined the cluster. == Verify Pacemaker Installation == Now that we have confirmed that Corosync is functional, we can check the rest of the stack. Pacemaker has already been started, so verify the necessary processes are running: ---- [root@pcmk-1 ~]# ps axf PID TTY STAT TIME COMMAND 2 ? S 0:00 [kthreadd] ...lots of processes... 11635 ? SLsl 0:03 corosync 11642 ? Ss 0:00 /usr/sbin/pacemakerd -f 11643 ? Ss 0:00 \_ /usr/libexec/pacemaker/cib 11644 ? Ss 0:00 \_ /usr/libexec/pacemaker/stonithd 11645 ? Ss 0:00 \_ /usr/libexec/pacemaker/lrmd 11646 ? Ss 0:00 \_ /usr/libexec/pacemaker/attrd 11647 ? Ss 0:00 \_ /usr/libexec/pacemaker/pengine 11648 ? Ss 0:00 \_ /usr/libexec/pacemaker/crmd ---- If that looks OK, check the `pcs status` output: ---- [root@pcmk-1 ~]# pcs status Cluster name: mycluster WARNING: no stonith devices and stonith-enabled is not false Stack: corosync Current DC: pcmk-2 (version 1.1.18-11.el7_5.3-2b07d5c5a9) - partition with quorum Last updated: Mon Sep 10 16:37:34 2018 Last change: Mon Sep 10 16:30:53 2018 by hacluster via crmd on pcmk-2 2 nodes configured 0 resources configured Online: [ pcmk-1 pcmk-2 ] No resources Daemon Status: corosync: active/disabled pacemaker: active/disabled pcsd: active/enabled ---- Finally, ensure there are no start-up errors from corosync or pacemaker (aside from messages relating to not having STONITH configured, which are OK at this point): ---- [root@pcmk-1 ~]# journalctl -b | grep -i error ---- [NOTE] ====== Other operating systems may report startup errors in other locations, for example +/var/log/messages+. ====== Repeat these checks on the other node. The results should be the same. + +== Explore the Existing Configuration == + +For those who are not of afraid of XML, you can see the raw cluster +configuration and status by using the `pcs cluster cib` command. + +.The last XML you'll see in this document +====== +---- +[root@pcmk-1 ~]# pcs cluster cib +---- +[source,XML] +---- + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +---- +====== + +Before we make any changes, it's a good idea to check the validity of +the configuration. + +---- +[root@pcmk-1 ~]# crm_verify -L -V + error: unpack_resources: Resource start-up disabled since no STONITH resources have been defined + error: unpack_resources: Either configure some or disable STONITH with the stonith-enabled option + error: unpack_resources: NOTE: Clusters with shared data need STONITH to ensure data integrity +Errors found during check: config not valid +---- + +As you can see, the tool has found some errors. The cluster will not start any +resources until we configure STONITH. diff --git a/doc/Clusters_from_Scratch/en-US/Clusters_from_Scratch.xml b/doc/Clusters_from_Scratch/en-US/Clusters_from_Scratch.xml index 7893d91adc..d69f167134 100644 --- a/doc/Clusters_from_Scratch/en-US/Clusters_from_Scratch.xml +++ b/doc/Clusters_from_Scratch/en-US/Clusters_from_Scratch.xml @@ -1,24 +1,24 @@ %BOOK_ENTITIES; ]> + -