Seagate ST43401N/ND Guia de Instalação descarregar pdf (Página 37)

CHAPTER 4 Plan: Writing a Plan and Getting Ready to Migrate

• Phased Cutover

Note This migration guide does not cover other parallel migration

approaches; such as running two systems in parallel where you have to

maintain both the systems simultaneously, or transaction duplication

where you use one front-end to drive two parallel back-ends. These system

operational approaches include factors too site-specific to detail

effectively in this guide.

Whenever possible, upgrade test and development databases to release

12.5 first. Upgrade the production system after testing. See Chapter 7,

“Test: Ensuring Stability and Performance” for more information about

testing.

Parallel With Replication

The issues for the parallel-with-replication approach are described in the

following sections:

Method

The following general method can be used to perform a parallel upgrade with

replication:

1 Install a new copy of ASE 12.5

2 Copy in or load pre-release 12.5 databases

3 Use Replication Server to maintain both sets of databases. The 12.5

system becomes the primary server, and you maintain the pre-12.5 system

as a warm standby.

Fallback

Plan for all users to reconnect to the earlier version server after you take ASE

12.5 offline. Make TCP/IP address and port changes where appropriate.

Test the fallback process as part of the application test suite. This suite should

do both of the following:

• Insert data into ASE 12.5. The data must be replicated and available in the

earlier server.

• Execute the fallback script.

Consider making daily

bcp dumps of the databases. To fall back, load the

dumps into the earlier server. Keep in mind:

• You may need to modify the databases to support incremental bcp dumps.

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Seagate ST43401N/ND Guia de Instalação Página 37