Kbase P7394: How to enable After-Imaging ?
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
5/21/2007 |
|
Status: Verified
GOAL:
How to enable After-Imaging ?
GOAL:
How to enable roll forward recovery ?
GOAL:
What are the steps involved in starting after-imaging from scratch ?
FIX:
It is highly recommended to read the Progress Documentation to assist in the decision making of your database disaster recovery plan. Furthermore, this plan should be tested and well documented before implementation.
It is generally accepted practice, that once after-imaging has been initiated, to then have cron jobs running unattended that back the after-image extents up and mark them as empty ready for re-use. Discussion of which is out of scope of this Solution.
Steps:
1.) The database structure must include after image extents:
create a dbname.st to add the ai extents
# example ai.st
# "extent_type" "extent_path_filename" "fixed/variable" "length"
a db/aidir/test.a1 f 2048
a db/aidir/test.a2
a db/aidir/test.a3
- ai extents can have more than 1 variable-length extent
- the fixed length of an extent must be a multiple of 16
- ai extents should be stored on a disc other than that which contains the database and/or bi files, but not stored remotely.
- the status of the ai extents must be monitored
2.) Shut down the database
It is not possible to start After-Imaging online. One of the reasons for this is that we need to mark the Master Block with After-Imaging enabled. It is not possible to do this when the database is running/in use.
proshut dbname -by
3.) Backup your database [optional but strongly recommended - see step 5]
probkup dbname path/preai.bak
prorest dbname path/preai.bak -vf # fully verify backup
4.) Add the After-Image (AI) extents to your schema (if they do not already exist)
prostrct add dbname ai.st
5.) Mark the database as backed-up
rfutil db -C mark backedup
[optional - see step 3]
- if "probkup" was used in step 3, this step is NOT necessary, the database is already stamped as backed up by the Progress probkup routine.
- if OS backup was used in step 3, this step IS absolutely necessary before starting after-imaging.
- if no_backup was taken in step 3, this step IS necessary, be very sure that the later online probkup of the database that is going to be used for roll forward recovery is synchronised.
6.) Start After-imaging.
rfutil dbname -C aimage begin
7.) Start the database
proserve dbname {parameters}