Re: How to corrupt oracle block

From: hpuxrac <johnbhurley_at_sbcglobal.net>
Date: 11 Nov 2005 09:40:40 -0800
Message-ID: <1131730840.656138.159850@f14g2000cwb.googlegroups.com>

Js wrote:
> Hi,
>
> I want to corrupt the oracle block for testing purpose on my test
> machine.
>
> Can one tall me how can we do this.
>
> I heard that we can do that using "dd" ...
>
> Please suggest.
>
> Regards,
> Js

Disclaimer severe damage may result. Make sure you have anything necessary backed up. Do not do this on a production system!

The best advice would be to open a tar with oracle and get them to supply info. But they won't do that ( at least easily ) when the subject is how to corrupt a block.

Then proceed carefully and do some queries to identify what block you want to wack!

The following script will ( perhaps ) work on a cooked file system.

• Script supplied by oracle in the advanced rman class ...

> more corrupt.sh

#!/bin/ksh
FILE=${1:?'Parameter 1 should be set to file name'} BLOCK=${2:?'Parameter 2 should be set to the block to be corrupted'} dd of=$FILE bs=8192 conv=notrunc oseek=$BLOCK <<EOF CORRUPT
EOF You may have to do something a little differently on a raw partition and perhaps adjust the seek value ( from what block oracle thinks it is ) ( varies by os and logical volume manager setup )

> more bad_block.sh

#!/bin/ksh
dd if=/home/oracle/badb13.dd of=/dev/vs_4/r_(fill_in_raw_partion)_.dbf bs=8192 seek=13 count=1

> more badb13.dd

************************ (just a bunch of characters or whatever you

want ) **** Received on Fri Nov 11 2005 - 11:40:40 CST