2. Key Concepts for Hardware Service Providers
3. Key Concepts for System Administrators and Application Developers
Cluster Configuration Repository (CCR)
Local and Global Namespaces Example
Using the cldevice Command to Monitor and Administer Disk Paths
Using Oracle Solaris Cluster Manager to Monitor Disk Paths
Using the clnode set Command to Manage Disk Path Failure
Adhering to Quorum Device Requirements
Adhering to Quorum Device Best Practices
Recommended Quorum Configurations
Quorum in Two-Host Configurations
Quorum in Greater Than Two-Host Configurations
Atypical Quorum Configurations
Characteristics of Scalable Services
Data Service API and Data Service Development Library API
Using the Cluster Interconnect for Data Service Traffic
Resources, Resource Groups, and Resource Types
Resource and Resource Group States and Settings
Resource and Resource Group Properties
Support for Oracle Solaris Zones
Support for Global-Cluster Non-Voting Nodes (Solaris Zones) Directly Through the RGM
Criteria for Using Support for Solaris Zones Directly Through the RGM
Requirements for Using Support for Solaris Zones Directly Through the RGM
Additional Information About Support for Solaris Zones Directly Through the RGM
Criteria for Using Oracle Solaris Cluster HA for Solaris Zones
Requirements for Using Oracle Solaris Cluster HA for Solaris Zones
Additional Information About Oracle Solaris Cluster HA for Solaris Zones
Data Service Project Configuration
Determining Requirements for Project Configuration
Setting Per-Process Virtual Memory Limits
Two-Host Cluster With Two Applications
Two-Host Cluster With Three Applications
Failover of Resource Group Only
Public Network Adapters and IP Network Multipathing
SPARC: Dynamic Reconfiguration Support
SPARC: Dynamic Reconfiguration General Description
SPARC: DR Clustering Considerations for CPU Devices
SPARC: DR Clustering Considerations for Memory
SPARC: DR Clustering Considerations for Disk and Tape Drives
SPARC: DR Clustering Considerations for Quorum Devices
SPARC: DR Clustering Considerations for Cluster Interconnect Interfaces
SPARC: DR Clustering Considerations for Public Network Interfaces
The Oracle Solaris Cluster software uses global devices to provide cluster-wide, highly available access to any device in a cluster, from any node, without regard to where the device is physically attached. In general, if a node fails while providing access to a global device, the Oracle Solaris Cluster software automatically discovers another path to the device. The Oracle Solaris Cluster software then redirects the access to that path. Oracle Solaris Cluster global devices include disks, CD-ROMs, and tapes. However, the only multiported global devices that Oracle Solaris Cluster software supports are disks. Consequently, CD-ROM and tape devices are not currently highly available devices. The local disks on each server are also not multiported, and thus are not highly available devices.
The cluster automatically assigns unique IDs to each disk, CD-ROM, and tape device in the cluster. This assignment enables consistent access to each device from any node in the cluster. The global device namespace is held in the /dev/global directory. See Global Namespace for more information.
Multiported global devices provide more than one path to a device. Because multihost disks are part of a device group that is hosted by more than one Oracle Solaris host, the multihost disks are made highly available.
The Oracle Solaris Cluster software manages shared devices through a construct known as the DID pseudo driver. This driver is used to automatically assign unique IDs to every device in the cluster, including multihost disks, tape drives, and CD-ROMs.
The DID pseudo driver is an integral part of the shared device access feature of the cluster. The DID driver probes all nodes of the cluster and builds a list of unique devices, assigns each device a unique major and a minor number that are consistent on all nodes of the cluster. Access to shared devices is performed by using the normalized DID logical name, instead of the traditional Oracle Solaris logical name, such as c0t0d0 for a disk.
This approach ensures that any application that accesses disks (such as a volume manager or applications that use raw devices) uses a consistent path across the cluster. This consistency is especially important for multihost disks, because the local major and minor numbers for each device can vary from host to host, thus changing the Oracle Solaris device naming conventions as well. For example, Host1 might identify a multihost disk as c1t2d0, and Host2 might identify the same disk completely differently, as c3t2d0. The DID framework assigns a common (normalized) logical name, such as d10, that the hosts use instead, giving each host a consistent mapping to the multihost disk.
You update and administer device IDs with the cldevice command. See the cldevice(1CL) man page.