Re: ORACLE data block corrupted

From: Neil Cudd <neil_at_cudd.demon.co.uk>
Date: Mon, 2 Apr 2001 12:17:53 +0100
Message-ID: <986210397.1754.0.nnrp-07.c2de6f3d@news.demon.co.uk>

"Howard J. Rogers" <howardjr_at_www.com> wrote in message news:3ac841d8_at_news.iprimus.com.au...
>
> "Dino Hsu" <dino1_at_ms1.hinet.net> wrote in message
> news:74ofctkitftdbhnqhpfonk17eikradlm1i_at_4ax.com...
> > On Sat, 31 Mar 2001 14:42:39 +0200, "Sybrand Bakker"
> > <postbus_at_sybrandb.demon.nl> wrote:
> >
> > >
> > >Datablock corrupted means there is an error on your disk.
> > >For now: you were lucky it is a rollback tablespace.
> > >Create an extra rollback segment in the tablespace system, drop the
 rollback
> > >tablespace, bringing the other rollback segments offline first of
 course,
> > >shutdown the database and make a backup (with verify!)

                                                          ^^^^^^


> > >Now remove the affected file

> > >Now check the disk

> > >If all is OK the bad spot doesn't belong to any file.

> > >Bring up the database and recreate your tablespace.

> > >And yes of course you will need to run upgrade scripts.

> > >

> > >Hth,

> > >

> > >Sybrand Bakker, Oracle DBA

> > >

> > >

> >

> > Sybrand & Howard,

> >

> > I appreciate your help very much because they are very helpful. I

> > would especially appreciate your in-time correction when I forgot

> > something I have learned in the DBA 1A class. The recovery part is

> > really a challenge to me.

> >

> > Here I have one more question:

> > Can you tell me the exact meaning about a backup with verify? I know

> > some backup procedures, but I am not sure which is the one you mean:

> > 1.export with exp80.exe

> > 2.ArcServe with Oracle Option

> > 3.Recover Manager

> > I like exp80.exe because it can be run when the database is open, and

> > we have more control on the objects we backup, but it seems you don't

> > mean exp80.exe.
> >
>
>
> I never think of export really as backing up the database -you certainly
> can't recover all your data using it. It's a relatively cheap and good
 way
> of recovering from the dropping of objects without the hassle of an
> incomplete recovery, but it shouldn't be your primary backup technique if
> recovering all data is a requirement.
>
> As for 'backup with verify', there are a couple of approaches. If you use
> Recovery Manager (which also allows control over what datafiles get backed
> up, and can do backups whilst the database is up and running), then the
> verification is implicit -if rman encounters block corruption, you'll know
> all about it pretty quickly!
>
> If you are doing old-fashion backups using operating system commands, then
> there is a utility, dbverify, which can be run against all the backup
 copies
> of the datafiles, and that will show up any corruption very quickly too.
> The unix command to run the utility is 'dbv'. I imagine in NT version 8,
 it
> was probably 'dbv80'. (It can also be used on datafiles which are in
 use).
>
> Haven't a clue about ArcServe, I'm afraid. Never used it.
>
> Regards
> HJR
I believe the database must be closed when running verifies on an NT database. dbv works on open files on Unix.

Regards,

Neil. Received on Mon Apr 02 2001 - 06:17:53 CDT