Chapter 1. Red Hat High Availability Add-On Configuration and Management Overview Red Hat High Availability Add-On allows you to connect a group of computers (called nodes or members ) to work together as a cluster. You can use Red Hat High Availability Add-On to suit your clustering needs (for example, setting up a cluster for sharing files on a GFS2 file system or setting up service failover). Note For information on best practices for deploying and upgrading Red Hat Enterprise Linux clusters using the High Availability Add-On and Red Hat Global File System 2 (GFS2) see the article "Red Hat Enterprise Linux Cluster, High Availability, and GFS Deployment Best Practices" on Red Hat Customer Portal at https://access.redhat.com/site/articles/40051 . This chapter provides a summary of documentation features and updates that have been added to the Red Hat High Availability Add-On since the initial release of Red Hat Enterprise Linux 6, followed by an overview of configuring and managing the Red Hat High Availability Add-On. 1.1. New and Changed Features This section lists new and changed features of the Red Hat High Availability Add-On documentation that have been added since the initial release of Red Hat Enterprise Linux 6. 1.1.1. New and Changed Features for Red Hat Enterprise Linux 6.1 Red Hat Enterprise Linux 6.1 includes the following documentation and feature updates and changes. As of the Red Hat Enterprise Linux 6.1 release and later, the Red Hat High Availability Add-On provides support for SNMP traps. For information on configuring SNMP traps with the Red Hat High Availability Add-On, see Chapter 11, SNMP Configuration with the Red Hat High Availability Add-On . As of the Red Hat Enterprise Linux 6.1 release and later, the Red Hat High Availability Add-On provides support for the ccs cluster configuration command. For information on the ccs command, see Chapter 6, Configuring Red Hat High Availability Add-On With the ccs Command and Chapter 7, Managing Red Hat High Availability Add-On With ccs . The documentation for configuring and managing Red Hat High Availability Add-On software using Conga has been updated to reflect updated Conga screens and feature support. For the Red Hat Enterprise Linux 6.1 release and later, using ricci requires a password the first time you propagate updated cluster configuration from any particular node. For information on ricci see Section 3.13, "Considerations for ricci " . You can now specify a Restart-Disable failure policy for a service, indicating that the system should attempt to restart the service in place if it fails, but if restarting the service fails the service will be disabled instead of being moved to another host in the cluster. This feature is documented in Section 4.10, "Adding a Cluster Service to the Cluster" and Appendix B, HA Resource Parameters . You can now configure an independent subtree as non-critical, indicating that if the resource fails then only that resource is disabled. For information on this feature see Section 4.10, "Adding a Cluster Service to the Cluster" and Section C.4, "Failure Recovery and Independent Subtrees" . This document now includes the new chapter Chapter 10, Diagnosing and Correcting Problems in a Cluster . In addition, small corrections and clarifications have been made throughout the document. 1.1.2. New and Changed Features for Red Hat Enterprise Linux 6.2 Red Hat Enterprise Linux 6.2 includes the following documentation and feature updates and changes. Red Hat Enterprise Linux now provides support for running Clustered Samba in an active/active configuration. For information on clustered Samba configuration, see Chapter 12, Clustered Samba Configuration . Any user able to authenticate on the system that is hosting luci can log in to luci . As of Red Hat Enterprise Linux 6.2, only the root user on the system that is running luci can access any of the luci components until an administrator (the root user or a user with administrator permission) sets permissions for that user. For information on setting luci permissions for users, see Section 4.3, "Controlling Access to luci" . The nodes in a cluster can communicate with each other using the UDP unicast transport mechanism. For information on configuring UDP unicast, see Section 3.12, "UDP Unicast Traffic" . You can now configure some aspects of luci 's behavior by means of the /etc/sysconfig/luci file. For example, you can specifically configure the only IP address luci is being served at. For information on configuring the only IP address luci is being served at, see Table 3.2, "Enabled IP Port on a Computer That Runs luci " . For information on the /etc/sysconfig/luci file in general, see Section 3.4, "Configuring luci with /etc/sysconfig/luci " . The ccs command now includes the --lsfenceopts option, which prints a list of available fence devices, and the --lsfenceopts fence_type option, which prints each available fence type. For information on these options, see Section 6.6, "Listing Fence Devices and Fence Device Options" . The ccs command now includes the --lsserviceopts option, which prints a list of cluster services currently available for your cluster, and the --lsserviceopts service_type option, which prints a list of the options you can specify for a particular service type. For information on these options, see Section 6.11, "Listing Available Cluster Services and Resources" . The Red Hat Enterprise Linux 6.2 release provides support for the VMware (SOAP Interface) fence agent. For information on fence device parameters, see Appendix A, Fence Device Parameters . The Red Hat Enterprise Linux 6.2 release provides support for the RHEV-M REST API fence agent, against RHEV 3.0 and later. For information on fence device parameters, see Appendix A, Fence Device Parameters . As of the Red Hat Enterprise Linux 6.2 release, when you configure a virtual machine in a cluster with the ccs command you can use the --addvm option (rather than the addservice option). This ensures that the vm resource is defined directly under the rm configuration node in the cluster configuration file. For information on configuring virtual machine resources with the ccs command, see Section 6.12, "Virtual Machine Resources" . This document includes a new appendix, Appendix D, Modifying and Enforcing Cluster Service Resource Actions . This appendix describes how rgmanager monitors the status of cluster resources, and how to modify the status check interval. The appendix also describes the __enforce_timeouts service parameter, which indicates that a timeout for an operation should cause a service to fail. This document includes a new section, Section 3.3.3, "Configuring the iptables Firewall to Allow Cluster Components" . This section shows the filtering you can use to allow multicast traffic through the iptables firewall for the various cluster components. In addition, small corrections and clarifications have been made throughout the document. 1.1.3. New and Changed Features for Red Hat Enterprise Linux 6.3 Red Hat Enterprise Linux 6.3 includes the following documentation and feature updates and changes. The Red Hat Enterprise Linux 6.3 release provides support for the condor resource agent. For information on HA resource parameters, see Appendix B, HA Resource Parameters . This document includes a new appendix, Appendix F, High Availability LVM (HA-LVM) . Information throughout this document clarifies which configuration changes require a cluster restart. For a summary of these changes, see Section 10.1, "Configuration Changes Do Not Take Effect" . The documentation now notes that there is an idle timeout for luci that logs you out after 15 minutes of inactivity. For information on starting luci , see Section 4.2, "Starting luci " . The fence_ipmilan fence device supports a privilege level parameter. For information on fence device parameters, see Appendix A, Fence Device Parameters . This document includes a new section, Section 3.14, "Configuring Virtual Machines in a Clustered Environment" . This document includes a new section, Section 5.6, "Backing Up and Restoring the luci Configuration" . This document includes a new section, Section 10.4, "Cluster Daemon crashes" . This document provides information on setting debug options in Section 6.14.4, "Logging" , Section 8.7, "Configuring Debug Options" , and Section 10.13, "Debug Logging for Distributed Lock Manager (DLM) Needs to be Enabled" . As of Red Hat Enterprise Linux 6.3, the root user or a user who has been granted luci administrator permissions can also use the luci interface to add users to the system, as described in Section 4.3, "Controlling Access to luci" . As of the Red Hat Enterprise Linux 6.3 release, the ccs command validates the configuration according to the cluster schema at /usr/share/cluster/cluster.rng on the node that you specify with the -h option. Previously the ccs command always used the cluster schema that was packaged with the ccs command itself, /usr/share/ccs/cluster.rng on the local system. For information on configuration validation, see Section 6.1.6, "Configuration Validation" . The tables describing the fence device parameters in Appendix A, Fence Device Parameters and the tables describing the HA resource parameters in Appendix B, HA Resource Parameters now include the names of those parameters as they appear in the cluster.conf file. In addition, small corrections and clarifications have been made throughout the document. 1.1.4. New and Changed Features for Red Hat Enterprise Linux 6.4 Red Hat Enterprise Linux 6.4 includes the following documentation and feature updates and changes. The Red Hat Enterprise Linux 6.4 release provides support for the Eaton Network Power Controller (SNMP Interface) fence agent, the HP BladeSystem fence agent, and the IBM iPDU fence agent. For information on fence device parameters, see Appendix A, Fence Device Parameters . Appendix B, HA Resource Parameters now provides a description of the NFS Server resource agent. As of Red Hat Enterprise Linux 6.4, the root user or a user who has been granted luci administrator permissions can also use the luci interface to delete users from the system. This is documented in Section 4.3, "Controlling Access to luci" . Appendix B, HA Resource Parameters provides a description of the new nfsrestart parameter for the Filesystem and GFS2 HA resources. This document includes a new section, Section 6.1.5, "Commands that Overwrite Settings" . Section 3.3, "Enabling IP Ports" now includes information on filtering the iptables firewall for igmp . The IPMI LAN fence agent now supports a parameter to configure the privilege level on the IPMI device, as documented in Appendix A, Fence Device Parameters . In addition to Ethernet bonding mode 1, bonding modes 0 and 2 are now supported for inter-node communication in a cluster. Troubleshooting advice in this document that suggests you ensure that you are using only supported bonding modes now notes this. VLAN-tagged network devices are now supported for cluster heartbeat communication. Troubleshooting advice indicating that this is not supported has been removed from this document. The Red Hat High Availability Add-On now supports the configuration of redundant ring protocol. For general information on using this feature and configuring the cluster.conf configuration file, see Section 8.6, "Configuring Redundant Ring Protocol" . For information on configuring redundant ring protocol with luci , see Section 4.5.4, "Configuring Redundant Ring Protocol" . For information on configuring redundant ring protocol with the ccs command, see Section 6.14.5, "Configuring Redundant Ring Protocol" . In addition, small corrections and clarifications have been made throughout the document. 1.1.5. New and Changed Features for Red Hat Enterprise Linux 6.5 Red Hat Enterprise Linux 6.5 includes the following documentation and feature updates and changes. This document includes a new section, Section 8.8, "Configuring nfsexport and nfsserver Resources" . The tables of fence device parameters in Appendix A, Fence Device Parameters have been updated to reflect small updates to the luci interface. In addition, many small corrections and clarifications have been made throughout the document. 1.1.6. New and Changed Features for Red Hat Enterprise Linux 6.6 Red Hat Enterprise Linux 6.6 includes the following documentation and feature updates and changes. The tables of fence device parameters in Appendix A, Fence Device Parameters have been updated to reflect small updates to the luci interface. The tables of resource agent parameters in Appendix B, HA Resource Parameters have been updated to reflect small updates to the luci interface. Table B.3, "Bind Mount ( bind-mount Resource) (Red Hat Enterprise Linux 6.6 and later)" documents the parameters for the Bind Mount resource agent. As of Red Hat Enterprise Linux 6.6 release, you can use the --noenable option of the ccs --startall command to prevent cluster services from being enabled, as documented in Section 7.2, "Starting and Stopping a Cluster" Table A.26, "Fence kdump" documents the parameters for the kdump fence agent. As of the Red Hat Enterprise Linux 6.6 release, you can sort the columns in a resource list on the luci display by clicking on the header for the sort category, as described in Section 4.9, "Configuring Global Cluster Resources" . In addition, many small corrections and clarifications have been made throughout the document. 1.1.7. New and Changed Features for Red Hat Enterprise Linux 6.7 Red Hat Enterprise Linux 6.7 includes the following documentation and feature updates and changes. This document now includes a new chapter, Chapter 2, Getting Started: Overview , which provides a summary procedure for setting up a basic Red Hat High Availability cluster. Appendix A, Fence Device Parameters now includes a table listing the parameters for the Emerson Network Power Switch (SNMP interface). Appendix A, Fence Device Parameters now includes a table listing the parameters for the fence_xvm fence agent, titled as "Fence virt (Multicast Mode"). The table listing the parameters for the fence_virt fence agent is now titled "Fence virt ((Serial/VMChannel Mode)". Both tables have been updated to reflect the luci display. Appendix A, Fence Device Parameters now includes a table listing the parameters for the fence_xvm fence agent, titled as "Fence virt (Multicast Mode"). The table listing the parameters for the fence_virt fence agent is now titled "Fence virt ((Serial/VMChannel Mode)". Both tables have been updated to reflect the luci display. The troubleshooting procedure described in Section 10.10, "Quorum Disk Does Not Appear as Cluster Member" has been updated. In addition, many small corrections and clarifications have been made throughout the document. 1.1.8. New and Changed Features for Red Hat Enterprise Linux 6.8 Red Hat Enterprise Linux 6.8 includes the following documentation and feature updates and changes. Appendix A, Fence Device Parameters now includes a table listing the parameters for the fence_mpath fence agent, titled as "Multipath Persistent Reservation Fencing". The table listing the parameters for the fence_ipmilan , fence_idrac , fence_imm , fence_ilo3 , and fence_ilo4 fence agents has been updated to reflect the luci display. Section F.3, "Creating New Logical Volumes for an Existing Cluster" now provides a procedure for creating new logical volumes in an existing cluster when using HA-LVM. 1.1.9. New and Changed Features for Red Hat Enterprise Linux 6.9 Red Hat Enterprise Linux 6.9 includes the following documentation and feature updates and changes. As of Red Hat Enterprise Linux 6.9, after you have entered a node name on the luci Create New Cluster dialog box or the Add Existing Cluster screen, the fingerprint of the certificate of the ricci host is displayed for confirmation, as described in Section 4.4, "Creating a Cluster" and Section 5.1, "Adding an Existing Cluster to the luci Interface" . Similarly, the fingerprint of the certificate of the ricci host is displayed for confirmation when you add a new node to a running cluster, as described in Section 5.3.3, "Adding a Member to a Running Cluster" . The luci Service Groups display for a selected service group now includes a table showing the actions that have been configured for each resource in that service group. For information on resource actions, see Appendix D, Modifying and Enforcing Cluster Service Resource Actions .

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