Seagate ST43401N/ND Informations techniques télécharger pdf (Page 48)

4-6 Prepare: Writing a Plan and Getting Ready to Migrate

Determine Migration Approach Adaptive Server Enterprise 11.5

Fallback Base fallback on the amount of time needed to restore earlier databases. For

example, if users need the system Monday at 8 a.m. and the restoration takes 8

hours, the validation test must pass by Sunday at midnight.

Note: Remember to include any client fallback in the calculation.

You can use dump database or bcp out before an upgrade to prepare for fallback.

Plan a way to capture transactions after cutover to be used in case of fallback. If

you go into production and then need to back off, you will have to restore all

the transactions that occurred after the last dump/load.

Application test suite For a development system, simple validation may be adequate. However, for a

production system, the test suite must address both update correctness and

performance acceptability.

See Chapter 7, “Test: Ensuring Stability and Performance” for more

information on testing.

Note: You might want to validate over a 3-day weekend if possible.

Fallback after cutover Consider making daily bcp dumps of the databases. You can then load the

dumps into release 10.x to fall back. Keep in mind:

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

• Pre-release 11.0 servers cannot read release 11.5 backup ﬁles. You need to

create bcp or other scripts to move tables back to pre-release 11.x.

• Do not use release 11.x schema enhancements, such as max_rows_per_page.

For information about scheduling backups of user databases, see the System

Administration Guide.

Bridging There should not be any user impact during migration. The more stringent the

validation test is, the less likely you will have bridging issues.

Environment Be sure to account for any increased release 11.5 memory requirements that

apply to your conﬁguration. For more information, see:

• The installation guide for your platform. It gives basic RAM requirements.

• Chapter 6, “Implement: Making Required Database Administration

Changes”.

• Details on conﬁguring memory and data caches in the System Administration

Guide

• Information on how to conﬁgure memory for performance in the Performance

and Tuning Guide.

Note: For a production system, execute the performance suite during off hours.

Scheduling For a development system, you may want to add a short period to the

development schedule for release 11.x issues.

For a production system, be prepared to postpone or back off if needed.

Table 4-3: Cutover migration (continued)

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Seagate ST43401N/ND Informations techniques Page 48