TruCluster Server Version 5.1A is a highly integrated synthesis of the Compaq Tru64TM UNIX operating system software, AlphaServerTM systems, and storage devices that operate as a single virtual system. Members of the cluster can share resources, data storage, and clusterwide file systems under a single security and management domain, yet they can boot or shut down independently without disrupting the cluster's services to clients.
A TruCluster Server environment can be as simple or as feature-rich as you require. You configure a cluster that fits your needs, from a two-node cluster up to an eight-node cluster running high availability applications such as transaction processing systems, servers for network client/server applications, data-sharing applications that require maximum uptime, and distributed parallel processing applications that take full advantage of the TruCluster Server application programming interfaces (APIs).
TruCluster Server includes a cluster alias for the Internet protocol suite (TCP/IP) so that a cluster appears as a single system to its network clients and peers.
This chapter provides the following information:
A list of the new or changed features for this release (Section 1.1)
A comprehensive table of TruCluster Server features (Section 1.2)
1.1 New or Changed Features for Version 5.1A
The following lists new or changed features for TruCluster Server Version 5.1A. Each item is accompanied by a pointer to a TruCluster Server manual, a section in this manual, or a reference page that provides information about that feature.
Support for local area network (LAN) hardware as the cluster interconnect (provides an alternative to Memory Channel). (See Chapter 7 and the Cluster LAN Interconnect manual for information on LAN cluster interconnects.)
Memory File System (MFS) and UNIX File System (UFS) read/write support (local member only). (See Table 2-1 and Cluster Administration.)
Cluster File System (CFS) performance enhancement — direct-access cached reads. (See Section 2.2.)
Cluster alias support for Network File System (NFS) clients using non-default cluster aliases when mounting and accessing NFS file systems that are exported by the cluster. (See Section 6.11.)
Logical Storage Manager (LSM) support for mirrored root
(/) and swap file systems.
(See
Cluster Administration
and
volmigrate(8).)
Quota support. (See Cluster Administration.)
User-initiated forced unmount of file systems.
(See
cfsmgr(8).)
1.2 TruCluster Server Features
TruCluster Server Version 5.1A provides
the features listed in
Table 1-1.
Table 1-1: Features in the TruCluster Server Version 5.1A Product
| Feature | Description |
| Clusterwide namespace | The
Cluster File System
(CFS) supports a single clusterwide namespace and uniform coherent
access to all
file systems in a cluster.
Context-dependent symbolic links (CDSLs) are used
to maintain per-system configuration and data files within the shared
CFS root ( See Section 2.2 for more information on CFS. See Section 2.5 for more information on CDSLs. |
| Clusterwide access to disk and tape storage | The device request dispatcher facility provides highly available clusterwide access to both character and block disk devices, as well as tape devices. All cluster disk and tape I/O passes through the device request dispatcher. See Section 2.3 for more information on the device request dispatcher. |
| Clusterwide Logical Storage Manager (LSM) | The semantics of LSM have been extended to a cluster environment. See Section 2.8 for more information on LSM in a cluster environment. |
| Connection manager | The connection manager ensures that all cluster members communicate with each other in order to control the formation and continued operation of a cluster. The connection manager calculates the votes required for quorum and decides when members are added to and removed from the cluster. See Chapter 3 for more information on the connection manager. |
| Cluster application availability (CAA) | The CAA facility provides resource monitoring and application restart capabilities. It provides the same type of application availability provided by user-defined services in the TruCluster Available Server Software and TruCluster Production Server Software products. See Chapter 4 for a definition of the types of applications that can run in a cluster. See Chapter 5 for more information on CAA's role in making single-instance applications highly available. |
| Cluster alias | The cluster alias subsystem lets TCP and UDP applications address the cluster as though it were a single system. When the cluster is created, a default cluster alias is defined that addresses all cluster members. A site can define additional aliases that address some or all cluster members. See Chapter 6 for more information on cluster aliases. |
| Highly available Network File System (NFS) server using cluster alias | As shipped, the cluster is a
highly available NFS server.
CFS ensures that file systems exported
from a TruCluster Server cluster are highly available to clients.
By default, clients use the default cluster alias as the name of the
NFS server when mounting file systems exported by the
cluster.
However, clients can also use an alias listed in the
See Section 6.11 for more information. |
| Highly available Internet services using cluster alias | As shipped, the cluster supports many
Internet services, such as
telnet
and
ftp
as highly available services.
These services are designated as
in_multi
services in the
/etc/clua_services
file, and the cluster alias subsystem
routes packets and
requests addressed to these services to available cluster members.
Nothing special was done to the services; the design of the cluster alias
subsystem makes this possible. |
| multiple cluster interconnects | TruCluster Server Version 5.1A supports either Memory Channel or local area network (LAN) hardware as the cluster interconnect. The Memory Channel interconnect is a high-speed interconnect designed specifically for the needs of clusters. TruCluster Server provides a Memory Channel application programming interface (API) library, which is the same as that provided in the TruCluster Production Server Software product. Support for a LAN cluster interconnect provides an alternative to Memory Channel when configuring a new cluster or upgrading an existing TruCluster ASE cluster. See the Cluster LAN Interconnect manual for detailed information on LAN cluster interconnects. See Chapter 7 for more information on LAN and Memory Channel interconnects. See the TruCluster Server Cluster Highly Available Applications manual for a description of the Memory Channel API. |
| Distributed lock manager (DLM) | TruCluster Server supports the DLM and its API, which is the same as that provided in the TruCluster Production Server Software product. See Chapter 8 for a description of the DLM. See the Cluster Highly Available Applications manual for a description of the DLM API. |
| Single-system management | Because a cluster uses CFS, all member systems' configuration files are available for management. The SysMan suite of graphical management utilities provides an integrated view of the cluster environment, letting you manage a single member or the entire cluster. See Chapter 9 for an overview of cluster installation and administration. |
| Rolling Upgrade | TruCluster Server Version 5.1A supports rolling upgrade. You can roll a cluster from TruCluster Server Version 5.1 to Version 5.1A. See Chapter 9 for more information. |
| File system partitioning | CFS makes it possible to mount an AdvFS file system so that it is accessible to only a single cluster member. This is referred to as file system partitioning. File system partitioning is provided in TruCluster Server to ease migration from TruCluster Production Server Software or TruCluster Available Server Software Version 1.5 or Version 1.6. File system partitioning is not intended as a general purpose method for restricting file system access to a single member. See
Cluster Administration
and
|
| Single Security Domain | Because a cluster uses CFS, there is a
single copy of security administration files such as
See the Tru64 UNIX Security manual for more information. |
| Expanded process IDs (PIDs) | PIDs are expanded to a full 32-bit value. PIDs are unique across a cluster. Each cluster member has a block of numbers that it assigns as PIDs. |