Full-System Cold Restore (ON-Archive) (SAP Library - SAP Database Guide: Informix (BC-DB-INF-DBA))

Full-System Cold Restore (ON-Archive)

Purpose

This section describes how to perform a full-system cold restore of your Informix database, if you use ON-Archive as your data recovery tool (that is, for your archives and backups).

You cannot use ON-Archive itself to perform a cold restore because it cannot access the sysmaster database for catalog information (because the database server is down). Therefore, you must use the ondatartr tool for the restore process.

You can specify a "Point-in-Time" (PIT) restore, during the logical restore stage.

Prerequisites

See Getting Started with Restore to make sure that you have already correctly identified the problem and chosen the right kind of restore.

Before you start, see Preparing for a Full-System Cold Restore (ON-Archive).

Process Flow

If there are logical logs that were not backed up at the time of the failure, you can salvage the logical logs.

You perform physical restore.

You perform logical restore.

Importance of Stages in Full-System Cold Restore (ON-Archive)

Stage	Stage required?	Effects of leaving out stage
Salvage logical log	Not always	Your database might be less up-to-date. You lose any transactions held in the logical log not backed up at time of failure.
Physical restore	Yes	You must always do at least a physical restore.
Logical restore	Yes for parallel archive and PIT restore	Your database might be less up-to-date. Without a logical restore, the latest transactions restored are those from the archive, that is, dbspace data without logical log data.

Result

Your database is now restored and can be used productively again.

See also:

Informix documentation