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Home -> Community -> Mailing Lists -> Oracle-L -> Re: How can I get the BBED password?
Wolfgang,
I have recently been looking at what types of corruption RMAN notices
and how it reports them. I used dd and BBED to experiment with =
intentional
block corruption in 9.2.0.6/HP-UX 11.11.
I have not had the time to conclude all the trials I want but BBED only =
marks=20
a block "FRACTURED" as seen in V$DATABASE_BLOCK_CORRUPTION
after RMAN's "BACKUP VALIDATE CHECK LOGICAL DATABASE" is run. =20
For this type of corruption RMAN does NOT fail with an error after =
backup=20
validation: it logs an entry to the alert log and inserts rows into=20
V$DATABASE_BLOCK_CORRUPTION and V$BACKUP_CORRUPTION. Alert log would =
show
such intentionally fractured block in the alert log as:
"Bad header found during backing up datafile"
without the usual "ORA-XXX".
RMAN behaved differently in a recent case where corrupted block was reported in alert log as:
"Bad header found during buffer read"
In that case RMAN failed with "ORA-19566: exceeded limit of 0 corrupt =
blocks for file".
It was also reported with "ORA-XXX" into the alert log. Unfortunately, =
I don't have=20
details on how it was reported in V$DATABASE_BLOCK_CORRUPTION.
I think it's important to know what kind of corruption RMAN can and =
cannot
report without the need to add auto monitoring of the alert log beyond =
the standard
"ORA-XXX" strings.
What I want to figure out conclusively by simulation is how RMAN reports =
the=20
other four types of corruption (as seen in V$DATABASE_BLOCK_CORRUPTION):
ALL ZERO, CHECKSUM, CORRUPT, LOGICAL
I will share my findings when I'm done, but in the meantime, I would =
welcome
your comments if you have any.
Cheers,
Slava Zayarny
Oracle DBA
Date: Wed, 13 Apr 2005 12:43:24 -0600
From: Wolfgang Breitling <breitliw_at_centrexcc.com>
Subject: Re: How can I get the BBED password?
I have used it to deliberately corrupt a block to find out how RMAN=20 report block corruptions. Of course there are other ways to corrupt=20 blocks but it seemed like a good excuse to build and use bbed.
Guerra, Abraham J wrote:
> Hello Tanel,
>=20
> Have you used the utility? If so, did you discover the password or =
=3D
> somebody else told it to you?
>=20
>=20
Wolfgang Breitling
Centrex Consulting Corporation
www.centrexcc.com
-- http://www.freelists.org/webpage/oracle-lReceived on Thu Apr 14 2005 - 10:00:05 CDT
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