Technical data

System Management Release Notes
5.9 OpenVMS Cluster Systems
did not test the current path first, and did not stay on that path if the error
condition had cleared.
5.10 OpenVMS Registry
The release notes in this section pertain to the OpenVMS Registry.
5.10.1 Registry Services in a Mixed OpenVMS V7.3/V7.2-1 Cluster
V7.3
Removing the data transfer size restrictions on the OpenVMS NT Registry
required a change in the communication protocol used by the Registry. The
change means that components of the Registry (the $REGISTRY system
service and the Registry server) in OpenVMS V7.3 are incompatible with their
counterparts in OpenVMS V7.2-1.
If you plan to run a cluster with mixed versions of OpenVMS, and you plan to use
the $REGISTRY service or a product that uses the $REGISTRY service (such as
Advanced Server, or COM for OpenVMS) then you are restricted to running these
services on the OpenVMS V7.3 nodes only, or on the V7.2-1 nodes only, but not
both.
If you need to run Registry services on both V7.3 and V7.2-1 nodes in the same
cluster, please contact your Compaq Services representative.
5.10.2 Backup and Restore of the OpenVMS NT Registry Database
V7.3
The backup and restore of the OpenVMS NT Registry database is discussed in
the OpenVMS Connectivity Developer Guide. Compaq would like to stress the
importance of periodic backups. Database corruptions are rare, but have been
exposed during testing of previous versions of OpenVMS with databases larger
than 2 megabytes. A database of this size is itself rare; initial database size is 8
kilobytes. The corruptions are further isolated by occurring only when rebooting
an entire cluster.
The Registry server provides a way of backing up the database automatically.
By default, the Registry server takes a snapshot of the database once per day.
However, this operation is basically a file copy and, by default, it purges the
copies to the most recent five. It is conceivable that a particular area of the
database may become corrupted and Registry operations will continue as long as
applications do not access that portion of the database. This means that the daily
backup could in fact be making a copy of an already corrupt file.
To safeguard against this, Compaq recommends that you take these additional
steps:
1. Ensure that the SYS$REGISTRY directory is part of your incremental or
full backup regimen, so that previous versions of the database are always
preserved. If, for example, you perform backups on a weekly basis, you may
want to increase the number of snapshot versions that are retained from 5 to
8. See the OpenVMS Connectivity Developer Guide for instructions on how to
change this parameter.
2. Periodically export the database. Exporting the database has several
advantages. First, it causes the server to read every key and value, so it
effectively performs a validation of the database. Second, it writes out the
database in a form that can be edited and repaired. This is not true of
5–26 System Management Release Notes