Reality Disaster Recovery
This section describes the configuration and administration
of Reality Disaster Recovery
Introduction
The Reality Disaster Recovery (Reality DR) feature provides a simple resilience facility for Reality databases. It can be used in various ways — for example:
-
To provide offsite replication of a standalone system. In particular, Reality DR can form part of a configuration that meets the requirements of ISO 17799:2005 Information Security Standard — refer to the ISO 17799 Directory for details.
Note: For true disaster recovery, it is recommended that the two systems should at least 10 km (6 miles) apart.
-
To increase the resilience of Reality FailSafe systems by providing a second backup system, which would normally be off site. This has two advantages:
- If the secondary system is taken down for maintenance purposes, you will remain protected against failure of the primary system.
- In a disaster situation where the computer room is destroyed, both the primary and secondary databases may be lost. An off site backup system ensures that your data remains secure.
In DR operation, the Reality systems take the role of master (this might be a failsafe primary or secondary) and slave (backup). The slave system is kept up to date by means of clean logs copied from the master. If the slave system becomes unavailable (because of a system crash or a broken link), operation of the master continues as before; transfer of the clean logs can resume when the slave again becomes available.
Activation of the backup system, should this become necessary, is a manual operation. See Recovering a Database using Disaster Recovery.
Reality Disaster Recovery
Reality Disaster Recovery (used with FailSafe)