Re: Undelete files on ext3 ??

John Bradford (john@grabjohn.com)
Wed, 8 Jan 2003 10:57:01 +0000 (GMT)


> > > > Therefore, it's time for somebody to put a 'dumpster` in all the Linux
> > > > file-systems. Somebody should then modify `rm` and the kernel unlink
> > > > to `mv' files to the dumpster directory on the file-system, instead of
> > > > really deleting them.

[snip discussion about a temporary directory for deleted files]

> Yes. But we could do better. Since no program uses the __syscall
> interface directly, wraping unlink in libc would affect all programs
> including rm. It could even be done withou recompiling anything using
> LD_PRELOAD.

I disagree. This is the wrong goal to be aiming for.

A temporary directory for deleted files can, and should be,
implemented in userspace.

What is much more interesting is the possibility of what I described
earlier in the thread as a virtual WORM device, and what Andreas
said could be done with LVM already using filesystem snapshots -
I.E. the ability to mount the filesystem as it was at any date and
time in the past.

However, as far as I can see, LVM snapshots are a manual process - the
user has to expressly create a snapshot when they want it.

What I was thinking of was a virtual device that allocated a new
sector whenever an old one was overwritten - kind of like a journaled
filesystem, but without the filesystem, (I.E. just the journal) :-).

John.
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