Before Installing HP DCE/9000 Version 1.7

Preinstallation Planning

Cell Directory Service Configuration

In configuring CDS servers and clients, pay careful attention to the HP DCE/ 9000 hardware requirements for the DCE product. (See “Hardware and Software Requirements” in this chapter.) Appropriate kernel configuration, memory, disk, and especially swap space are essential to the proper functioning of the CDS subsystem.

Tape backups of the CDS server database are extremely important for recovery from catastrophic problems. HP strongly recommends regular tape back ups of all CDS server databases, especially those containing any master replicas. Tape backups and restorations require the CDS server in question to be temporarily shut down.

Most CDS problems, however, do not require resorting to tape backup. Directory replication provides continuous online backup for most failures, with faster recovery and less stale data. This makes directory replication highly desirable for all DCE cells. Every cell should configure at least two CDS servers, and read-only replicas of all directories should be created on the backup server. In this configuration, backup is continuous, and recovery only involves switching the role of the servers.

Multiple CDS servers can be configured for specific purposes in the cell. Multiple CDS servers with read-only replicas of all directories in the name space should always be present for backup and recovery purposes. Performance considerations may also make the configuration of other CDS servers desirable. For instance, administrators of very busy cells or cells with large numbers of nodes should consider adding additional CDS servers to share the name space processing load. Similarly, administrators of cells with groups of nodes separated by WAN links should consider providing a local CDS server for each group to enhance performance. Administrators with very large cells may want to partition the name space among several CDS servers, replicating only the locally used directories, to distribute the storage overhead of the name space.

Each of these CDS configuration strategies is documented in the OSF DCE Administration Guide — Core Services.

Time Services

A minimum of three DTS servers is recommended for any cell with three or more member systems. If you use an external time provider, you can have only one of these running in a cell.

Planning and Configuring HP DCE 1.7

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