Re: ORACLE data block corrupted

From: Sybrand Bakker <postbus_at_sybrandb.demon.nl>
Date: Mon, 2 Apr 2001 07:01:15 +0200
Message-ID: <tch8j7n9mjhdf3@beta-news.demon.nl>

"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.
>
> Regards,
> Dino
>

Exp is a *logical* backup. I was discussing a *physical* backup, as evidently logical isn't applicable in this case, and the database *definitely needs to be down* to avoid more havoc. If you already have disk problems, new disk problems can potentially surface any time, any place. So, yes, I was discussing a backup *with verify* which means the backup utility is comparing the data on tape to the data on disk. A backup without verify is simply no backup. In the past I was more than once unable to restore a backup without verify which showed succesfull completion. ArcServe should be capable of doing that, I have never worked with RMAN (as that doesn't integrate with O/S backup procedures like Arcserve does)

Hth,

Sybrand Bakker, Oracle DBA Received on Mon Apr 02 2001 - 00:01:15 CDT