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Re: Delete Datafile and Recover DB Without Using Backup?

From: mkb <>
Date: Tue, 1 Mar 2005 09:11:53 -0800 (PST)
Message-ID: <>

With linux ext2 file systems, this is possible using debugfs. This won't work with the newer ext3 file system though
(see for further info on why).

There is a lot of information out there on whether this can be done or not. Basically my question comes down to "is there a unix undelete feature". And basically the answer is "no" unless you really, really know the particular *nix file system architecture you have and are able to write code to hook into the kernel (ala Norton Tools for Unix circa early 90's which had this feature).

Aliasing rm to copy the file somewhere can be done, but consider that some database files can be in the GB range, so for all intents and purposes this might not be practical.

Before giving up in my attempts to find a stasifactory answer, I came across this little article:

Looks promising. In a nutshell, if a process has a file open and if another session rm's it, the inode is still open/avaiable.

Get all users off, shutdown all processes except the process that has the rm'd file open, crash the system, come up in single user mode then fsck the system.

Anyway, more details in the above link.

No, I have not tested any of the above.

Having just started a new position I believe it would be prudent if I refrained from "playing around" on any systems for a while. But I will try this out on a test box eventually and hopefuly, post my results.


--- Tim Gorman <> wrote:

> ...your luck will have to extend as far as the
> session also having SYSDBA
> privileges, which is required to use the
> And, if your RECID/STAMP combination points to tape
> media, then Shared
> Server (MTS) would be a hindrance, not an aid, as I
> believe that RMAN MMV
> "shared libraries" require "dedicated server".
> on 2/24/05 6:11 PM, Jeremiah Wilton at
> wrote:
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Received on Tue Mar 01 2005 - 12:15:07 CST

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