Re: DB recovery from journals

I used to provide support for journaling at Rochester and I have seen some
of the worst situations that you can imagine, but data was never lost.  The
one that I remember well is the client who journaled through a reorg and
then needed to apply the changes.  He had to apply the changes to the
reorg, then reorg, then apply the changes that occured after the reorg.  If
you have everything in the correct order it should go without a hitch.  One
known issue is with passing dates from Query400.

Dan Jahr




"Graap, Ken" <keg@gasco.gasco.com> on 04/01/99 05:06:20 PM

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 Subject: DB recovery from journals                           
                                                              








Hello all...

I'm planning to perform a disaster recovery test using journals. We will be
simulating a loss of our production system between backups and would like
to
recover right up to the time of failure. I would like this test to be
successful so I need to completely understand how to do it before I spend
thousands of $$$'s trying... <smile>

I am currently journaling all production DB files to a remote system via
the
remote journaling support in OS/400.

*** The production database, along with the journal is located in library:
SOURCEDB on our production (source) system

*** The local journal receivers are located in library: SOURCERCV on the
production (source) system.

*** Remote journaling is defined using library redirection to library:
TARGETRCV on our remote journaling (target) system.
      As receivers are replicated to the target system they are
automatically deleted from the source system.

I  regularly back up my production database and remote journal receivers
via
SAVLIB commands on both systems.

---------------------------------------------------------------------------
-
-------------------------------------

Here is how I believe I'd recover my production system at a disaster
recovery site:

I arrive at the site with B/U tapes from both my production (source) system
and my remote journaling (target) system.

After restoring LIC, OS/400 and all that stuff I would then:

1.) Restore the SOURCEDB library to library SOURCEDB on the disaster
recovery system

2.) Restore the journal receivers from library TARGETRCV to library
SOURCERCV on the disaster recovery system.

3.) Insure that the receiver chain is correct and current using the  "Work
with Receiver Directory" display.
      If it isn't then I'd use the  "Associate Receivers With Journal"
option from the WRKJRN display.

4.) Apply journal changes via the "Forward Recovery" option from the WRKJRN
display.

My questions for this distinguished group are....
Is it really this simple?
Has anyone done a recovery like this?
Are there any "gotchas" I need to know about?
Am I correct in assuming I can just restore the receivers from the target
system and easily associate them with the restored journal from the source
system prior to applying them to the DB files?

thanx in advance for all your input, and wish me luck with my test... :)


Kenneth

--
********************************
       Kenneth  E.  Graap
    IBM Certified Specialist
          AS/400   Professional
          System  Administrator
 NW Natural - Information Services
           System Services
        503 226 4211 X5537
          FAX  503 721 2521
      keg@nwnatural.com
********************************

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