Planning and Configuring HP DCE 1.8

Chapter 3 65
Before Installing HP DCE/9000 Version 1.8
Preinstallation Planning
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.
Eachof theseCDS configuration strategies is documentedin 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.
If you are running AFS, be sure to run the AFS daemon (afsd) with the
-nosettime option. Otherwise, afsd periodically resets the system's
time. Also be sure that no other software that sets the time (like ntp or
timed) is running on the systems in the cell.
See the OSF DCE Administration Guide -- Core Services for more
information about DCE Distributed Time Services.
At this release, intercell time synchronization is not supported.