Cluster Server 8.0.2 Administrator's Guide - Linux
- Section I. Clustering concepts and terminology
- Introducing Cluster Server
- About Cluster Server
- About cluster control guidelines
- About the physical components of VCS
- Logical components of VCS
- Types of service groups
- About resource monitoring
- Agent classifications
- About cluster control, communications, and membership
- About security services
- Components for administering VCS
- About cluster topologies
- VCS configuration concepts
- Introducing Cluster Server
- Section II. Administration - Putting VCS to work
- About the VCS user privilege model
- Administering the cluster from the command line
- About administering VCS from the command line
- About installing a VCS license
- Administering LLT
- Starting VCS
- Stopping the VCS engine and related processes
- Logging on to VCS
- About managing VCS configuration files
- About managing VCS users from the command line
- About querying VCS
- About administering service groups
- Modifying service group attributes
- About administering resources
- Enabling and disabling IMF for agents by using script
- Linking and unlinking resources
- About administering resource types
- About administering clusters
- Configuring applications and resources in VCS
- VCS bundled agents for UNIX
- Configuring NFS service groups
- About NFS
- Configuring NFS service groups
- Sample configurations
- About configuring the RemoteGroup agent
- About configuring Samba service groups
- About testing resource failover by using HA fire drills
- Predicting VCS behavior using VCS Simulator
- Section III. VCS communication and operations
- About communications, membership, and data protection in the cluster
- About cluster communications
- About cluster membership
- About membership arbitration
- About membership arbitration components
- About server-based I/O fencing
- About majority-based fencing
- About the CP server service group
- About secure communication between the VCS cluster and CP server
- About data protection
- Examples of VCS operation with I/O fencing
- About cluster membership and data protection without I/O fencing
- Examples of VCS operation without I/O fencing
- Administering I/O fencing
- About the vxfentsthdw utility
- Testing the coordinator disk group using the -c option of vxfentsthdw
- About the vxfenadm utility
- About the vxfenclearpre utility
- About the vxfenswap utility
- About administering the coordination point server
- About configuring a CP server to support IPv6 or dual stack
- About migrating between disk-based and server-based fencing configurations
- Migrating between fencing configurations using response files
- Controlling VCS behavior
- VCS behavior on resource faults
- About controlling VCS behavior at the service group level
- About AdaptiveHA
- Customized behavior diagrams
- About preventing concurrency violation
- VCS behavior for resources that support the intentional offline functionality
- VCS behavior when a service group is restarted
- About controlling VCS behavior at the resource level
- VCS behavior on loss of storage connectivity
- Service group workload management
- Sample configurations depicting workload management
- The role of service group dependencies
- About communications, membership, and data protection in the cluster
- Section IV. Administration - Beyond the basics
- VCS event notification
- VCS event triggers
- Using event triggers
- List of event triggers
- Virtual Business Services
- Section V. Veritas High Availability Configuration wizard
- Introducing the Veritas High Availability Configuration wizard
- Administering application monitoring from the Veritas High Availability view
- Administering application monitoring from the Veritas High Availability view
- Administering application monitoring from the Veritas High Availability view
- Section VI. Cluster configurations for disaster recovery
- Connecting clusters–Creating global clusters
- VCS global clusters: The building blocks
- About global cluster management
- About serialization - The Authority attribute
- Prerequisites for global clusters
- Setting up a global cluster
- Configuring clusters for global cluster setup
- Configuring service groups for global cluster setup
- About IPv6 support with global clusters
- About cluster faults
- About setting up a disaster recovery fire drill
- Test scenario for a multi-tiered environment
- Administering global clusters from the command line
- About global querying in a global cluster setup
- Administering clusters in global cluster setup
- Setting up replicated data clusters
- Setting up campus clusters
- Connecting clusters–Creating global clusters
- Section VII. Troubleshooting and performance
- VCS performance considerations
- How cluster components affect performance
- How cluster operations affect performance
- VCS performance consideration when a system panics
- About scheduling class and priority configuration
- VCS agent statistics
- About VCS tunable parameters
- Troubleshooting and recovery for VCS
- VCS message logging
- Gathering VCS information for support analysis
- Troubleshooting the VCS engine
- Troubleshooting Low Latency Transport (LLT)
- Troubleshooting Group Membership Services/Atomic Broadcast (GAB)
- Troubleshooting VCS startup
- Troubleshooting issues with systemd unit service files
- Troubleshooting service groups
- Troubleshooting resources
- Troubleshooting sites
- Troubleshooting I/O fencing
- Fencing startup reports preexisting split-brain
- Troubleshooting CP server
- Troubleshooting server-based fencing on the VCS cluster nodes
- Issues during online migration of coordination points
- Troubleshooting notification
- Troubleshooting and recovery for global clusters
- Troubleshooting licensing
- Licensing error messages
- Troubleshooting secure configurations
- Troubleshooting wizard-based configuration issues
- Troubleshooting issues with the Veritas High Availability view
- VCS message logging
- VCS performance considerations
- Section VIII. Appendixes
About cluster formation with different versions of the VCS engine
The Cluster Server component (VCS) of InfoScale Availability requires all the nodes in a cluster to run the same version of the VCS engine, also known as the high availability daemon or HAD. On each node, HAD operates as a replicated state machine (RSM), which means that all the nodes that form the cluster have a synchronized state of the cluster configuration. InfoScale supports a rolling upgrade of the nodes in a cluster but the process involves some downtime of the VCS engine. VCS upgrade is therefore a two-phased process: in the first phase, the installer upgrades the kernel filesets. In the second phase, the installer upgrades VCS and the VCS agent filesets.
Starting with version 7.4.2, InfoScale allows for the formation of clusters with nodes that run different versions of the VCS engine. It does so by providing a framework that lets you:
Add nodes with newer versions of the VCS engine to an existing cluster
Upgrade InfoScale on one node at a time without the need for a cluster-wide HA downtime
Manage the simultaneous usage of multiple VCS engine versions by using the cluster protocol number
The concept of a cluster protocol number is introduced, which determines whether a node that runs a particular VCS version can become part of a cluster. An internal, system-level attribute, SupportedProtocol
, is provided to store the supported cluster protocol number.
To identify the cluster protocol number that is supported by each node in a cluster, run the following commend:
# haclus -version -info
To identify the protocol number that is currently used by the cluster, run the following command
# haclus -value ProtocolNumber
When a cluster is formed with different versions of the VCS engine, the lowest supported cluster protocol number is used by all the nodes to maintain the RSM. The use of a supported cluster protocol number ensures consistent behaviour across cluster nodes during operations like startup, snapshot exchange, group failover, and so on. If the VCS engine is not compatible with the SupportedProtocol
of the new nodes that are being added to the cluster, the cluster does not accept the new node and maintains the status quo of the RSM.
Note:
This framework supports cluster formation with different versions of VCS only if the nodes run InfoScale 7.4.2 or later.
For a node to join an existing cluster, it should run the VCS engine with the minimum supported cluster protocol number.