Red Hat Enterprise Linux 4 Cluster Administration Configuring and Managing a Red Hat Cluster Edition 1.
Red Hat Enterprise Linux 4 Cluster Administration Configuring and Managing a Red Hat Cluster Edition 1.0 Landmann rlandmann@redhat.
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Table of Contents Table of Contents .Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5. . . . . . . . . . 1. Document Conventions 6 1.1. T ypographic Conventions 6 1.2. Pull-quote Conventions 7 1.3. Notes and Warnings 8 2. Feedback 8 .Chapter . . . . . . . . 1. . . .Red . . . . Hat . . . . .Cluster . . . . . . . .Configuration . . . . . . . . . . . . . . and . .
Red Hat Enterprise Linux 4 Cluster Administration .Chapter ........4 . ...Managing . . . . . . . . . . .Red . . . . Hat . . . . Cluster . . . . . . . . With . . . . . .Conga . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4. .7. . . . . . . . . . 4.1. Starting, Stopping, and Deleting Clusters 47 4.2. Managing Cluster Nodes 47 4.3. Managing High-Availability Services 48 4.4. Diagnosing and Correcting Problems in a Cluster 49 .Chapter . . . . . . . . 5. . . .
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Red Hat Enterprise Linux 4 Cluster Administration 4
Introduction Introduction T his document provides information about installing, configuring and managing Red Hat Cluster components. Red Hat Cluster components are part of Red Hat Cluster Suite and allow you to connect a group of computers (called nodes or members) to work together as a cluster. T his document does not include information about installing, configuring, and managing Linux Virtual Server (LVS) software. Information about that is in a separate document.
Red Hat Enterprise Linux 4 Cluster Administration Red Hat Cluster Suite documentation and other Red Hat documents are available in HT ML, PDF, and RPM versions on the Red Hat Enterprise Linux Documentation CD and online at http://www.redhat.com/docs/. 1. Document Conventions T his manual uses several conventions to highlight certain words and phrases and draw attention to specific pieces of information. In PDF and paper editions, this manual uses typefaces drawn from the Liberation Fonts set.
Introduction T o insert a special character into a gedit file, choose Applications → Accessories → Character Map from the main menu bar. Next, choose Search → Find… from the Character Map menu bar, type the name of the character in the Search field and click Next. T he character you sought will be highlighted in the Character T able. Double-click this highlighted character to place it in the T ext to copy field and then click the Copy button.
Red Hat Enterprise Linux 4 Cluster Administration static int kvm_vm_ioctl_deassign_device(struct kvm *kvm, struct kvm_assigned_pci_dev *assigned_dev) { int r = 0; struct kvm_assigned_dev_kernel *match; mutex_lock(&kvm->lock); match = kvm_find_assigned_dev(&kvm->arch.
Introduction Be sure to mention the manual's identifier: Cluster_Administration(EN)-4.8 (2009-5-13T12:45) By mentioning this manual's identifier, we know exactly which version of the guide you have. If you have a suggestion for improving the documentation, try to be as specific as possible. If you have found an error, please include the section number and some of the surrounding text so we can find it easily.
Red Hat Enterprise Linux 4 Cluster Administration Chapter 1. Red Hat Cluster Configuration and Management Overview Red Hat Cluster allows you to connect a group of computers (called nodes or members) to work together as a cluster. You can use Red Hat Cluster to suit your clustering needs (for example, setting up a cluster for sharing files on a GFS file system or setting up service failover). 1.1.
Chapter 1. Red Hat Cluster Configuration and Management Overview Figure 1.1. Red Hat Cluster Hardware Overview 1.1.2. Installing Red Hat Cluster software T o install Red Hat Cluster software, you must have entitlements for the software. If you are using the Conga configuration GUI, you can let it install the cluster software. If you are using other tools to configure the cluster, secure and install the software as you would with Red Hat Enterprise Linux software. 1.1.3.
Red Hat Enterprise Linux 4 Cluster Administration Figure 1.2. Cluster Configuration Structure T he following cluster configuration tools are available with Red Hat Cluster: Conga — T his is a comprehensive user interface for installing, configuring, and managing Red Hat clusters, computers, and storage attached to clusters and computers. system -config-cluster — T his is a user interface for configuring and managing a Red Hat cluster.
Chapter 1. Red Hat Cluster Configuration and Management Overview Integration of Cluster Status and Logs Fine-Grained Control over User Permissions T he primary components in Conga are luci and ricci, which are separately installable. luci is a server that runs on one computer and communicates with multiple clusters and computers via ricci. ricci is an agent that runs on each computer (either a cluster member or a standalone computer) managed by Conga.
Red Hat Enterprise Linux 4 Cluster Administration Figure 1.3. luci homebase T ab Figure 1.4 .
Chapter 1. Red Hat Cluster Configuration and Management Overview Figure 1.5. luci storage T ab 1.3. system-config-cluster Cluster Administration GUI T his section provides an overview of the cluster administration graphical user interface (GUI) available with Red Hat Cluster Suite — system -config-cluster. It is for use with the cluster infrastructure and the high-availability service management components.
Red Hat Enterprise Linux 4 Cluster Administration Figure 1.6. Cluster Configuration T ool T he Cluster Configuration T ool represents cluster configuration components in the configuration file (/etc/cluster/cluster.conf) with a hierarchical graphical display in the left panel. A triangle icon to the left of a component name indicates that the component has one or more subordinate components assigned to it. Clicking the triangle icon expands and collapses the portion of the tree below a component.
Chapter 1. Red Hat Cluster Configuration and Management Overview resources consist of file systems, IP addresses, NFS mounts and exports, and user-created scripts that are available to any high-availability service in the cluster. Resources are represented as subordinate elements under Resources. Using configuration buttons at the bottom of the right frame (below Properties), you can create resources (when Resources is selected) or edit resource properties (when a resource is selected).
Red Hat Enterprise Linux 4 Cluster Administration T he nodes and services displayed in the Cluster Status T ool are determined by the cluster configuration file (/etc/cluster/cluster.conf). You can use the Cluster Status T ool to enable, disable, restart, or relocate a high-availability service. 1.4.
Chapter 2. Before Configuring a Red Hat Cluster Chapter 2. Before Configuring a Red Hat Cluster T his chapter describes tasks to perform and considerations to make before installing and configuring a Red Hat Cluster, and consists of the following sections: Section 2.1, “Compatible Hardware” Section 2.2, “Enabling IP Ports” Section 2.3, “Configuring ACPI For Use with Integrated Fence Devices” Section 2.4, “Configuring max_luns” Section 2.5, “Considerations for Using Quorum Disk” Section 2.
Red Hat Enterprise Linux 4 Cluster Administration T able 2.1. Enabled IP Ports on Red Hat Cluster Nodes IP Port Number Protocol Component Reference to Example of iptables Rules 6809 UDP cm an (Cluster Manager), for use in clusters with Distributed Lock Manager (DLM) selected Example 2.1, “Port 6809: cman” 11111 T CP ricci (part of Conga remote agent) Example 2.3, “Port 11111: ricci (Cluster Node and Computer Running luci)” 14567 T CP gnbd (Global Network Block Device) Example 2.
Chapter 2. Before Configuring a Red Hat Cluster T able 2.2. Enabled IP Ports on a Computer T hat Runs luci IP Port Number Protocol Component Reference to Example of iptables Rules 8084 T CP luci (Conga user interface server) Example 2.2, “Port 8084: luci (Cluster Node or Computer Running luci)” 11111 T CP ricci (Conga remote agent) Example 2.3, “Port 11111: ricci (Cluster Node and Computer Running luci)” 2.2.3.
Red Hat Enterprise Linux 4 Cluster Administration Example 2.5. Port 16851: modclusterd -A INPUT -i 10.10.10.200 -m state --state NEW -m multiport -p tcp -s 10.10.10.0/24 -d 10.10.10.0/24 --dports 16851 -j ACCEPT Example 2.6. Port 21064 : dlm -A INPUT -i 10.10.10.200 -m state --state NEW -m multiport -p tcp -s 10.10.10.0/24 -d 10.10.10.0/24 --dports 21064 -j ACCEPT Example 2.7. Ports 4 004 0, 4 004 2, 4 104 0: lock_gulmd -A INPUT -i 10.10.10.200 -m state --state NEW -m multiport -p tcp -s 10.10.10.
Chapter 2. Before Configuring a Red Hat Cluster completely rather than attempting a clean shutdown (for example, shutdown -h now). Otherwise, if ACPI Soft-Off is enabled, an integrated fence device can take four or more seconds to turn off a node (refer to note that follows). In addition, if ACPI Soft-Off is enabled and a node panics or freezes during shutdown, an integrated fence device may not be able to turn off the node. Under those circumstances, fencing is delayed or unsuccessful.
Red Hat Enterprise Linux 4 Cluster Administration Note T his is the preferred method of disabling ACPI Soft-Off. Disable ACPI Soft-Off with chkconfig management at each cluster node as follows: 1. Run either of the following commands: chkconfig --del acpid — T his command removes acpid from chkconfig management. — OR — chkconfig --level 234 5 acpid off — T his command turns off acpid. 2. Reboot the node. 3. When the cluster is configured and running, verify that the node turns off immediately when fenced.
Chapter 2. Before Configuring a Red Hat Cluster Note You can fence the node with the fence_node command or Conga. Example 2.11.
Red Hat Enterprise Linux 4 Cluster Administration 4. When the cluster is configured and running, verify that the node turns off immediately when fenced. Note You can fence the node with the fence_node command or Conga. Example 2.12. Kernel Boot Command Line with acpi=off Appended to It # grub.conf generated by anaconda # # Note that you do not have to rerun grub after making changes to this file # NOTICE: You have a /boot partition.
Chapter 2. Before Configuring a Red Hat Cluster # cd /boot # mkinitrd -f -v initrd-kernel.img kernel For example, the currently running kernel in the following m kinitrd command is 2.6.9-34.0.2.EL: # mkinitrd -f -v initrd-2.6.9-34.0.2.EL.img 2.6.9-34.0.2.EL Note You can determine the currently running kernel by running unam e -r. 5. Restart the node. 2.5.
Red Hat Enterprise Linux 4 Cluster Administration failed nodes on its own, and can take much longer to do so than CMAN. T he default value for CMAN membership timeout is 10 seconds. Other site-specific conditions may affect the relationship between the membership timeout values of CMAN and qdiskd. For assistance with adjusting the CMAN membership timeout value, contact an authorized Red Hat support representative. Fencing T o ensure reliable fencing when using qdiskd, use power fencing.
Chapter 2. Before Configuring a Red Hat Cluster 2.8. General Configuration Considerations You can configure a Red Hat Cluster in a variety of ways to suit your needs. T ake into account the following considerations when you plan, configure, and implement your Red Hat Cluster.
Red Hat Enterprise Linux 4 Cluster Administration Chapter 3. Configuring Red Hat Cluster With Conga T his chapter describes how to configure Red Hat Cluster software using Conga, and consists of the following sections: Section 3.1, “Configuration T asks” Section 3.2, “Starting luci and ricci”. Section 3.3, “Creating A Cluster” Section 3.4, “Global Cluster Properties” Section 3.5, “Configuring Fence Devices” Section 3.6, “Configuring Cluster Members” Section 3.7, “Configuring a Failover Domain” Section 3.
Chapter 3. Configuring Red Hat Cluster With Conga Note T ypically, a computer in a server cage or a data center hosts luci; however, a cluster computer can host luci. 4. At the computer running luci, initialize the luci server using the luci_adm in init command. For example: # luci_admin init Initializing the Luci server Creating the 'admin' user Enter password: Confirm password: Please wait...
Red Hat Enterprise Linux 4 Cluster Administration 4. Click Subm it. Clicking Subm it causes the the Create a new cluster page to be displayed again, showing the parameters entered in the preceding step, and Lock Manager parameters. T he Lock Manager parameters consist of the lock manager option buttons, DLM (preferred) and GULM, and Lock Server text boxes in the GULM lock server properties group box.
Chapter 3. Configuring Red Hat Cluster With Conga T he Post-Fail Delay parameter is the number of seconds the fence daemon (fenced) waits before fencing a node (a member of the fence domain) after the node has failed. T he PostFail Delay default value is 0. Its value may be varied to suit cluster and network performance. T he Post-Join Delay parameter is the number of seconds the fence daemon (fenced) waits before fencing a node after the node joins the fence domain.
Red Hat Enterprise Linux 4 Cluster Administration Note Clicking Apply on the Quorum Partition tab propagates changes to the cluster configuration file (/etc/cluster/cluster.conf) in each cluster node. However, for the quorum disk to operate, you must restart the cluster (refer to Section 4.1, “Starting, Stopping, and Deleting Clusters”). T able 3.1. Quorum-Disk Parameters Parameter Description Do not use a Quorum Partition Disables quorum partition.
Chapter 3. Configuring Red Hat Cluster With Conga example, name, IP address, login, and password). Modifying a fence device consists of selecting an existing fence device and changing parameters for that fence device. Deleting a fence device consists of selecting an existing fence device and deleting it. Note If you are creating a new cluster, you can create fence devices when you configure cluster nodes. Refer to Section 3.6, “Configuring Cluster Members”.
Red Hat Enterprise Linux 4 Cluster Administration causes the display of menu items for fence device configuration: Add a Fence Device and Configure a Fence Device. Note If this is an initial cluster configuration, no fence devices have been created, and therefore none are displayed. 2. Click Add a Fence Device. Clicking Add a Fence Device causes the Add a Sharable Fence Device page to be displayed (refer to Figure 3.1, “Fence Device Configuration”). Figure 3.1. Fence Device Configuration 3.
Chapter 3. Configuring Red Hat Cluster With Conga 1. At the detailed menu for the cluster (below the clusters menu), click Shared Fence Devices. Clicking Shared Fence Devices causes the display of the fence devices for a cluster and causes the display of menu items for fence device configuration: Add a Fence Device and Configure a Fence Device. 2. Click Configure a Fence Device. Clicking Configure a Fence Device causes the display of a list of fence devices under Configure a Fence Device. 3.
Red Hat Enterprise Linux 4 Cluster Administration Note You can choose from an existing fence device or create a new fence device. 5. Click Update m ain fence properties and wait for the change to take effect. 3.6.2. Adding a Member to a Running Cluster T o add a member to a running cluster, follow the steps in this section. T he starting point of the procedure is at the cluster-specific page that you navigate to from Choose a cluster to adm inister displayed on the cluster tab. 1.
Chapter 3. Configuring Red Hat Cluster With Conga 10. Click Update m ain fence properties and wait for the change to take effect. 3.6.3. Deleting a Member from a Cluster T o delete a member from an existing cluster that is currently in operation, follow the steps in this section. T he starting point of the procedure is at the Choose a cluster to adm inister page (displayed on the cluster tab). 1. Click the link of the node to be deleted.
Red Hat Enterprise Linux 4 Cluster Administration member at the top of the list is the most preferred, followed by the second member in the list, and so on. Note Changing a failover domain configuration has no effect on currently running services. Note Failover domains are not required for operation. By default, failover domains are unrestricted and unordered.
Chapter 3. Configuring Red Hat Cluster With Conga 4. T o enable setting failover priority of the members in the failover domain, click the Prioritized checkbox. With Prioritized checked, you can set the priority value, Priority, for each node selected as members of the failover domain. 5. T o restrict failover to members in this failover domain, click the checkbox next to Restrict failover to this domain's members.
Red Hat Enterprise Linux 4 Cluster Administration a node means that the node is a member of the failover domain. If Prioritized is checked, you can adjust the priority in the Priority text box for each member of the failover domain. 8. Click Subm it. Clicking Subm it causes a progress page to be displayed followed by the display of the Failover Dom ain Form page. T hat page displays the added resource and includes the failover domain in the cluster menu to the left under Domain. 9.
Chapter 3. Configuring Red Hat Cluster With Conga is unchecked. Force Unmount kills all processes using the mount point to free up the mount when it tries to unmount. Reboot host node if unmount fails — If checked, reboots the node if unmounting this file system fails. T he default setting is unchecked. Check file system before mounting — If checked, causes fsck to be run on the file system before mounting it. T he default setting is unchecked. IP Address IP Address — T ype the IP address for the resource.
Red Hat Enterprise Linux 4 Cluster Administration 4. Click Subm it. Clicking Subm it causes a progress page to be displayed followed by the display of Resources forcluster name page. T hat page displays the added resource (and other resources). 3.9. Adding a Cluster Service to the Cluster T o add a cluster service to the cluster, follow the steps in this section.
Chapter 3. Configuring Red Hat Cluster With Conga Note T o verify the existence of the IP service resource used in a cluster service, you must use the /sbin/ip addr list command on a cluster node. T he following output shows the /sbin/ip addr list command executed on a node running a cluster service: 1: lo: mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.
Red Hat Enterprise Linux 4 Cluster Administration Partitions Volume Groups Each section is set up as an expandable tree, with links to property sheets for specific devices, partitions, and storage entities. Configure the storage for your cluster to suit your cluster requirements. If you are configuring Red Hat GFS, configure clustered logical volumes first, using CLVM. For more information about CLVM and GFS refer to Red Hat documentation for those products.
Chapter 4. Managing Red Hat Cluster With Conga Chapter 4. Managing Red Hat Cluster With Conga T his chapter describes various administrative tasks for managing a Red Hat Cluster and consists of the following sections: Section 4.1, “Starting, Stopping, and Deleting Clusters” Section 4.2, “Managing Cluster Nodes” Section 4.3, “Managing High-Availability Services” Section 4.4, “Diagnosing and Correcting Problems in a Cluster” 4.1.
Red Hat Enterprise Linux 4 Cluster Administration Make a node leave or join a cluster. Fence a node. Reboot a node. Delete a node. T o perform one the functions in the preceding list, follow the steps in this section. T he starting point of the procedure is at the cluster-specific page that you navigate to from Choose a cluster to adm inister displayed on the cluster tab. 1. At the detailed menu for the cluster (below the clusters menu), click Nodes.
Chapter 4. Managing Red Hat Cluster With Conga causes the display of services for the cluster in the center of the page. 2. At the right of each service listed on the page, click the Choose a task drop-down box. Clicking Choose a task drop-down box reveals the following selections depending on if the service is running: If service is running — Configure this service, Restart this service, and Stop this service. If service is not running — Configure this service, Start this service, and Delete this service.
Red Hat Enterprise Linux 4 Cluster Administration Chapter 5. Configuring Red Hat Cluster With system-configcluster T his chapter describes how to configure Red Hat Cluster software using system -config-cluster, and consists of the following sections: Section 5.1, “Configuration T asks” Section 5.2, “Starting the Cluster Configuration T ool” Section 5.3, “Configuring Cluster Properties” Section 5.4, “Configuring Fence Devices” Section 5.5, “Adding and Deleting Members” Section 5.
Chapter 5. Configuring Red Hat Cluster With system-config-cluster Configuration T ool on cluster node nano-01, do the following: 1. Log in to a cluster node and run system -config-cluster. For example: $ ssh -Y root@nano-01 . . . # system-config-cluster 2. If this is the first time you have started the Cluster Configuration T ool, the program prompts you to either open an existing configuration or create a new one. Click Create New Configuration to start a new configuration file (refer to Figure 5.
Red Hat Enterprise Linux 4 Cluster Administration Disk Heuristic. T able 5.1, “Quorum-Disk Parameters” describes the parameters. Important Quorum-disk parameters and heuristics depend on the site environment and special requirements needed. T o understand the use of quorum-disk parameters and heuristics, refer to the qdisk(5) man page. If you require assistance understanding and using quorum disk, contact an authorized Red Hat support representative.
Chapter 5. Configuring Red Hat Cluster With system-config-cluster Figure 5.2. Creating A New Configuration 4. When you have completed entering the cluster name and other parameters in the New Configuration dialog box, click OK. Clicking OK starts the Cluster Configuration T ool, displaying a graphical representation of the configuration (Figure 5.3, “T he Cluster Configuration T ool”).
Red Hat Enterprise Linux 4 Cluster Administration Figure 5.3.
Chapter 5. Configuring Red Hat Cluster With system-config-cluster T able 5.1. Quorum-Disk Parameters Parameter Description Use a Quorum Disk Enables quorum disk. Enables quorum-disk parameters in the New Configuration dialog box. Interval T he frequency of read/write cycles, in seconds. T KO T he number of cycles a node must miss in order to be declared dead. Votes T he number of votes the quorum daemon advertises to CMAN when it has a high enough score.
Red Hat Enterprise Linux 4 Cluster Administration httpd_cluster). T he cluster alias cannot exceed 15 characters. 4. (Optional) T he Config Version value is set to 1 by default and is automatically incremented each time you save your cluster configuration. However, if you need to set it to another value, you can specify it at the Config Version text box. 5. Specify the Fence Daemon Properties parameters (DLM clusters only): Post-Join Delay and Post-Fail Delay. a.
Chapter 5. Configuring Red Hat Cluster With system-config-cluster 3. Specify the information in the Fence Device Configuration dialog box according to the type of fence device. Refer to Appendix B, Fence Device Parameters for more information about fence device parameters. 4. Click OK. 5. Choose File => Save to save the changes to the cluster configuration. 5.5.
Red Hat Enterprise Linux 4 Cluster Administration Figure 5.6. Adding a Member to a New GULM Cluster 3. At the Cluster Node Name text box, specify a node name. T he entry can be a name or an IP address of the node on the cluster subnet. Note Each node must be on the same subnet as the node from which you are running the Cluster Configuration T ool and must be defined either in DNS or in the /etc/hosts file of each cluster node.
Chapter 5. Configuring Red Hat Cluster With system-config-cluster h. T o create additional fence devices at this fence level, return to step 6d. Otherwise, proceed to the next step. i. T o create additional fence levels, return to step 6c. Otherwise, proceed to the next step. j. If you have configured all the fence levels and fence devices for this node, click Close. 7. Choose File => Save to save the changes to the cluster configuration. T o continue configuring a new cluster, proceed to Section 5.
Red Hat Enterprise Linux 4 Cluster Administration 7. Start system -config-cluster (refer to Section 5.2, “Starting the Cluster Configuration T ool”). At the Cluster Configuration T ool tab, verify that the configuration is correct. At the Cluster Status T ool tab verify that the nodes and services are running as expected. Note Make sure to configure other parameters that may be affected by changes in this section. Refer to Section 5.1, “Configuration T asks”. 5.5.2.2.
Chapter 5. Configuring Red Hat Cluster With system-config-cluster c. service clvm d stop, if CLVM has been used to create clustered volumes d. service fenced stop e. service cm an stop f. service ccsd stop 3. At system -config-cluster (running on a node that is not to be deleted), in the Cluster Configuration T ool tab, delete the member as follows: a. If necessary, click the triangle icon to expand the Cluster Nodes property. b. Select the cluster node to be deleted.
Red Hat Enterprise Linux 4 Cluster Administration Note Make sure to configure other parameters that may be affected by changes in this section. Refer to Section 5.1, “Configuration T asks”. 5.5.4.
Chapter 5. Configuring Red Hat Cluster With system-config-cluster T o delete a member functioning only as a GULM client from an existing cluster that is currently in operation, follow these steps: 1. At one of the running nodes (not at a node to be deleted), start system -config-cluster (refer to Section 5.2, “Starting the Cluster Configuration T ool”). At the Cluster Status T ool tab, under Services, disable or relocate each service that is running on the node to be deleted. 2.
Red Hat Enterprise Linux 4 Cluster Administration d. service gfs start, if you are using Red Hat GFS e. service rgm anager start, if the cluster is running high-availability services (rgm anager) 6. At system -config-cluster (running on a node that was not deleted), in the Cluster Configuration T ool tab, verify that the configuration is correct. At the Cluster Status T ool tab verify that the nodes and services are running as expected.
Chapter 5. Configuring Red Hat Cluster With system-config-cluster b. Select the cluster node to be deleted. At the bottom of the right frame (labeled Properties), click the Delete Node button. c. Clicking the Delete Node button causes a warning dialog box to be displayed requesting confirmation of the deletion (Figure 5.9, “Confirm Deleting a Member”). Figure 5.9. Confirm Deleting a Member d. At that dialog box, click Yes to confirm deletion. 5.
Red Hat Enterprise Linux 4 Cluster Administration Note Make sure to configure other parameters that may be affected by changes in this section. Refer to Section 5.1, “Configuration T asks”. 5.6. Configuring a Failover Domain A failover domain is a named subset of cluster nodes that are eligible to run a cluster service in the event of a node failure.
Chapter 5. Configuring Red Hat Cluster With system-config-cluster Section 5.6.1, “Adding a Failover Domain” Section 5.6.2, “Removing a Failover Domain” Section 5.6.3, “Removing a Member from a Failover Domain” 5.6.1. Adding a Failover Domain T o add a failover domain, follow these steps: 1. At the left frame of the the Cluster Configuration T ool, click Failover Domains. 2. At the bottom of the right frame (labeled Properties), click the Create a Failover Dom ain button.
Red Hat Enterprise Linux 4 Cluster Administration Adjusting Priority”). Clicking Prioritized List causes the Priority column to be displayed next to the Member Node column. Figure 5.11. Failover Domain Configuration: Adjusting Priority b. For each node that requires a priority adjustment, click the node listed in the Member Node/Priority columns and adjust priority by clicking one of the Adjust Priority arrows.
Chapter 5. Configuring Red Hat Cluster With system-config-cluster New cluster — If this is a new cluster, choose File => Save to save the changes to the cluster configuration. Running cluster — If this cluster is operational and running, and you want to propagate the change immediately, click the Send to Cluster button. Clicking Send to Cluster automatically saves the configuration change.
Red Hat Enterprise Linux 4 Cluster Administration system ID explicitly, specify it in this field. Force Unmount checkbox — If checked, forces the file system to unmount. T he default setting is unchecked. Force Unmount kills all processes using the mount point to free up the mount when it tries to unmount. With GFS resources, the mount point is not unmounted at service tear-down unless this box is checked. File System Name — Create a name for the file system resource.
Chapter 5. Configuring Red Hat Cluster With system-config-cluster Read-Write and Read Only options — Specify the type of access rights for this NFS client resource: Read-Write — Specifies that the NFS client has read-write access. T he default setting is Read-Write. Read Only — Specifies that the NFS client has read-only access. Options — Additional client access rights. For more information, refer to the exports(5) man page, General Options NFS Export Name — Enter a name for the NFS export resource.
Red Hat Enterprise Linux 4 Cluster Administration Note Use a descriptive name that clearly distinguishes the service from other services in the cluster. Figure 5.12. Adding a Cluster Service 4. If you want to restrict the members on which this cluster service is able to run, choose a failover domain from the Failover Domain drop-down box. (Refer to Section 5.6, “Configuring a Failover Domain” for instructions on how to configure a failover domain.) 5.
Chapter 5. Configuring Red Hat Cluster With system-config-cluster 7. Select a recovery policy to specify how the resource manager should recover from a service failure. At the upper right of the Service Managem ent dialog box, there are three Recovery Policy options available: Restart — Restart the service in the node the service is currently located. T he default setting is Restart. If the service cannot be restarted in the the current node, the service is relocated.
Red Hat Enterprise Linux 4 Cluster Administration For newly defined clusters, you must propagate the configuration file to the cluster nodes as follows: 1. Log in to the node where you created the configuration file. 2. Using the scp command, copy the /etc/cluster/cluster.conf file to all nodes in the cluster. Note Propagating the cluster configuration file this way is necessary for the first time a cluster is created.
Chapter 6. Managing Red Hat Cluster With system-config-cluster Chapter 6. Managing Red Hat Cluster With system-configcluster T his chapter describes various administrative tasks for managing a Red Hat Cluster and consists of the following sections: Section 6.1, “Starting and Stopping the Cluster Software” Section 6.2, “Managing High-Availability Services” Section 6.4, “Backing Up and Restoring the Cluster Database” Section 6.5, “Disabling the Cluster Software” Section 6.
Red Hat Enterprise Linux 4 Cluster Administration Figure 6.1. Cluster Status T ool You can use the Cluster Status T ool to enable, disable, restart, or relocate a high-availability service. T he Cluster Status T ool displays the current cluster status in the Services area and automatically updates the status every 10 seconds. T o enable a service, you can select the service in the Services area and click Enable. T o disable a service, you can select the service in the Services area and click Disable.
Chapter 6. Managing Red Hat Cluster With system-config-cluster T able 6.1. Members Status Members Status Member Description T he node is part of the cluster. Note: A node can be a member of a cluster; however, the node may be inactive and incapable of running services. For example, if rgm anager is not running on the node, but all other cluster software components are running in the node, the node appears as a Member in the Cluster Status T ool.
Red Hat Enterprise Linux 4 Cluster Administration Important Although the Cluster Configuration T ool provides a Quorum Votes parameter in the Properties dialog box of each cluster member, that parameter is intended only for use during initial cluster configuration. Furthermore, it is recommended that you retain the default Quorum Votes value of 1. For more information about using the Cluster Configuration T ool, refer to Chapter 5, Configuring Red Hat Cluster With system-config-cluster.
Chapter 6. Managing Red Hat Cluster With system-config-cluster file /etc/cluster/cluster.conf.bak.1 is the newest backup, /etc/cluster/cluster.conf.bak.2 is the second newest backup, and /etc/cluster/cluster.conf.bak.3 is the third newest backup. If a cluster member becomes inoperable because of misconfiguration, restore the configuration file according to the following steps: 1. At the Cluster Configuration T ool tab of the Red Hat Cluster Suite management GUI, click File => Open. 2.
Red Hat Enterprise Linux 4 Cluster Administration # # # # # # # chkconfig chkconfig chkconfig chkconfig chkconfig chkconfig chkconfig --level --level --level --level --level --level --level 2345 2345 2345 2345 2345 2345 2345 rgmanager off gfs off clvmd off fenced off lock_gulmd off cman off ccsd off Once the problems with the disabled cluster member have been resolved, use the following commands to allow the member to rejoin the cluster: # # # # # # # chkconfig chkconfig chkconfig chkconfig chkconfig
Example of Setting Up Apache HTTP Server Example of Setting Up Apache HTTP Server T his appendix provides an example of setting up a highly available Apache HT T P Server on a Red Hat Cluster. T he example describes how to set up a service to fail over an Apache HT T P Server. Variables in the example apply to this example only; they are provided to assist setting up a service that suits your requirements. Note T his example uses the Cluster Configuration T ool (system -config-cluster).
Red Hat Enterprise Linux 4 Cluster Administration step. Specify the drive letter and the partition number. For example: # mkfs -t ext3 /dev/sde3 3. Mount the file system that contains the document root directory. For example: # mount /dev/sde3 /var/www/html Do not add this mount information to the /etc/fstab file because only the cluster software can mount and unmount file systems used in a service. 4. Copy all the required files to the document root directory. 5.
Example of Setting Up Apache HTTP Server AllowOverride None Options None Order allow,deny Allow from all Additional changes may need to be made to tune the Apache HT T P Server or add module functionality. For information on setting up other options, refer to the Red Hat Enterprise Linux System Administration Guide and the Red Hat Enterprise Linux Reference Guide. 2. T he standard Apache HT T P Server start script, /etc/rc.d/init.
Red Hat Enterprise Linux 4 Cluster Administration choose each resource that you created in the previous steps. Repeat this step until all resources have been added. Click OK. 6. Choose File => Save to save your changes.
Fence D evice Parameters Fence Device Parameters T his appendix provides tables with parameter descriptions of fence devices. Note Certain fence devices have an optional Password Script parameter. T he Password Scriptparameter allows specifying that a fence-device password is supplied from a script rather than from the Password parameter. Using the Password Script parameter supersedes the Password parameter, allowing passwords to not be visible in the cluster configuration file (/etc/cluster/cluster.
Red Hat Enterprise Linux 4 Cluster Administration T able B.3. Bull PAP (Platform Administration Processor) Field Description Name A name for the Bull PAP system connected to the cluster. IP Address T he IP address assigned to the PAP console. Login T he login name used to access the PAP console. Password T he password used to authenticate the connection to the PAP console. Password Script (optional) T he script that supplies a password for access to the fence device.
Fence D evice Parameters T able B.6. Fujitsu Siemens Remoteview Service Board (RSB) Field Description Name A name for the RSB to use as a fence device. Hostname T he hostname assigned to the device. Login T he login name used to access the device. Password T he password used to authenticate the connection to the device. Password Script (optional) T he script that supplies a password for access to the fence device. Using this supersedes the Password parameter. T able B.7.
Red Hat Enterprise Linux 4 Cluster Administration T able B.10. IBM Remote Supervisor Adapter II (RSA II) Field Description Name A name for the RSA device connected to the cluster. Hostname T he hostname assigned to the device. Login T he login name used to access the device. Password T he password used to authenticate the connection to the device. Password Script (optional) T he script that supplies a password for access to the fence device. Using this supersedes the Password parameter.
Fence D evice Parameters Warning Manual fencing is not supported for production environments. T able B.14 . McData SAN Switch Field Description Name A name for the McData device connected to the cluster. IP Address T he IP address assigned to the device. Login T he login name used to access the device. Password T he password used to authenticate the connection to the device. Password Script (optional) T he script that supplies a password for access to the fence device.
Red Hat Enterprise Linux 4 Cluster Administration T able B.18. Virtual Machine Fencing Field Description Name Name of the virtual machine fencing device. Domain Unique domain name of the guest to be fenced. T able B.19. Vixel SAN Switch Field Description Name A name for the Vixel switch connected to the cluster. IP Address T he IP address assigned to the device. Password T he password used to authenticate the connection to the device.
Revision History Revision History Revision 1.0-10.4 00 Rebuild with publican 4.0.0 2013-10-31 Rüdiger Landmann Revision 1.0-10 Rebuild for Publican 3.0 2012-07-18 Anthony T owns Revision 1.0-0 Mon Apr 13 2009 Index A ACPI - configuring, Configuring ACPI For Use with Integrated Fence Devices Apache HT T P Server - httpd.
Red Hat Enterprise Linux 4 Cluster Administration - enabling IP ports, Enabling IP Ports - general considerations, General Configuration Considerations - managing cluster node, Managing Cluster Nodes - managing high-availability services, Managing High-Availability Services - modifying the cluster configuration, Modifying the Cluster Configuration - restoring the cluster database, Backing Up and Restoring the Cluster Database - SELinux, Red Hat Cluster Suite and SELinux - starting and stopping the cluster
Revision History command line tools table, Command Line Administration T ools configuration file - propagation of, Propagating T he Configuration File: New Cluster configuring cluster storage , Configuring Cluster Storage Conga - accessing, Configuring Red Hat Cluster Software - considerations for cluster administration, Considerations for Using Conga - overview, Conga Conga overview, Conga F feedback, Feedback G general - considerations for cluster administration, General Configuration Considerations
Red Hat Enterprise Linux 4 Cluster Administration iptables - configuring, Enabling IP Ports M max_luns - configuring, Configuring max_luns P parameters, fence device, Fence Device Parameters power controller connection, configuring, Fence Device Parameters power switch, Fence Device Parameters - (see also power controller) Q qdisk - considerations for using, Considerations for Using Quorum Disk quorum disk - considerations for using, Considerations for Using Quorum Disk S SELinux - configuring, Red Ha
