Will Reisefs have "undo"?

Will Reisefs have "undo"?

[Joachim Zobel]

Hi.

Are there any plans to add undo capabilities to reiserfs? Most modern
desktops have a trash can. Am I the only one who has idea that this is a
crappy workaround for something that should be in the filesystem. 

I am aware that this is not easy, but nearly everybody has had moments
where he would have loved it. And disk space is cheap, there is rarely
the need to overwrite anything.

Sincerely,
Joachim

-- 
"... ein Geschlecht erfinderischer Zwerge, die fuer alles gemietet werden 
koennen."                            - Bertolt Brecht - Leben des Galilei 

Re: Will Reisefs have "undo"?

[Fred -- Speed Up --]

This is not the filesystem's work, KDE for instance has a trashcan, and you
can bind the rm command to a special mv one that moves files from the
initial place to a backup folder, the files of which you can empty regulary
with a cron script depending on the file's "age". It's simple to implement,
and really not something Reiser4 should be capable of ... instead
journalising works very well to protect data from being erased, that's the
only purpose of a modern filesystem.

Fred

----- Original Message ----- 
From: "Joachim Zobel" <nc-zobeljo@netcologne.de>
To: "ReiserFS List" <reiserfs-list@namesys.com>
Sent: Saturday, June 14, 2003 8:38 PM
Subject: Will Reisefs have "undo"?


> Hi.
>
> Are there any plans to add undo capabilities to reiserfs? Most modern
> desktops have a trash can. Am I the only one who has idea that this is a
> crappy workaround for something that should be in the filesystem.
>
> I am aware that this is not easy, but nearly everybody has had moments
> where he would have loved it. And disk space is cheap, there is rarely
> the need to overwrite anything.
>
> Sincerely,
> Joachim
>
> -- 
> "... ein Geschlecht erfinderischer Zwerge, die fuer alles gemietet werden
> koennen."                            - Bertolt Brecht - Leben des Galilei
>
>

Re: Will Reisefs have "undo"?

[Pierre Abbat]

On Saturday 14 June 2003 14:38, Joachim Zobel wrote:
> Hi.
>
> Are there any plans to add undo capabilities to reiserfs? Most modern
> desktops have a trash can. Am I the only one who has idea that this is a
> crappy workaround for something that should be in the filesystem.
>
> I am aware that this is not easy, but nearly everybody has had moments
> where he would have loved it. And disk space is cheap, there is rarely
> the need to overwrite anything.

I agree. I once moved a serverful of files from the old server (ext2) to the 
new server (reiser) and deleted them from the old server. Some of the files 
got somehow lost and I had to get them back with e2undel. A reiserundel 
program would be nice.

phma
-- 
.i toljundi do .ibabo mi'afra tu'a do
.ibabo damba do .ibabo do jinga
.icu'u la ma'atman.

Re: Will Reisefs have "undo"?

[Joachim Zobel]

Am Sam, 2003-06-14 um 21.39 schrieb Fred -- Speed Up --:
> This is not the filesystem's work, KDE for instance has a trashcan, and you
> can bind the rm command to a special mv one that moves files from the
> initial place to a backup folder, the files of which you can empty regulary
> with a cron script depending on the file's "age". It's simple to implement,
> and really not something Reiser4 should be capable of ... instead
> journalising works very well to protect data from being erased, that's the
> only purpose of a modern filesystem.

A filesystem undo is most needed on servers. There usually is no KDE.
However a trash can can be done with hard links and a cronjob. What I
would like to have is more - I think I was not clear enough about that.
I not only want to undo deletions. I would like to be able to undo all
file system operations. 

VMS has a versioning file system, which does about what I want. It feels
pretty good if you can undo "everything I did since 11:30".

Joachim

-- 
"... ein Geschlecht erfinderischer Zwerge, die fuer alles gemietet werden 
koennen."                            - Bertolt Brecht - Leben des Galilei 

Re: Will Reisefs have "undo"?

[Dieter Nützel]

Am Sonntag, 15. Juni 2003 11:50 schrieb Joachim Zobel:
> Am Sam, 2003-06-14 um 21.39 schrieb Fred -- Speed Up --:
> > This is not the filesystem's work, KDE for instance has a trashcan, and
> > you can bind the rm command to a special mv one that moves files from the
> > initial place to a backup folder, the files of which you can empty
> > regulary with a cron script depending on the file's "age". It's simple to
> > implement, and really not something Reiser4 should be capable of ...
> > instead journalising works very well to protect data from being erased,
> > that's the only purpose of a modern filesystem.
>
> A filesystem undo is most needed on servers.

No.

> There usually is no KDE.

True.

> However a trash can can be done with hard links and a cronjob.

True.

> What I would like to have is more - I think I was not clear enough about
> that. I not only want to undo deletions. I would like to be able to undo all
> file system operations.

What you are looking for are FS snapshots.
LVM or EVMS can do that with all (?) Linux FSs.

> VMS has a versioning file system, which does about what I want.

Windows 2003 Server (very new feature ;-), too. 
But it is a bloated thing.

> It feels pretty good if you can undo "everything I did since 11:30".

You should have some TRUE backups (snapshots) handy.

-- 
Dieter Nützel
Leiter F&E, WEAR-A-BRAIN GmbH, Wiener Str. 5, 28359 Bremen, Germany
Mobil: 0162 673 09 09

Re: Will Reisefs have "undo"?

[Alex Malinovich]

[-- Attachment #1: Type: text/plain, Size: 1812 bytes --]

On Sun, 2003-06-15 at 07:09, Dieter Nützel wrote:
> Am Sonntag, 15. Juni 2003 11:50 schrieb Joachim Zobel:
> > Am Sam, 2003-06-14 um 21.39 schrieb Fred -- Speed Up --:
> > > This is not the filesystem's work, KDE for instance has a trashcan, and
> > > you can bind the rm command to a special mv one that moves files from the
> > > initial place to a backup folder, the files of which you can empty
> > > regulary with a cron script depending on the file's "age". It's simple to
> > > implement, and really not something Reiser4 should be capable of ...
> > > instead journalising works very well to protect data from being erased,
> > > that's the only purpose of a modern filesystem.
> >
> > A filesystem undo is most needed on servers.
--snip--
> > What I would like to have is more - I think I was not clear enough about
> > that. I not only want to undo deletions. I would like to be able to undo all
> > file system operations.
--snap--
> > It feels pretty good if you can undo "everything I did since 11:30".

I don't think snapshots are really needed. I would be perfectly content
with a "semi-intelligent" filesystem that would mark files as deleted in
the journal while leaving the file intact on the HD. As soon as the file
has actually been overwritten, it is marked "purged" and cannot be
recovered. But up to that point, it would be a relatively simple task to
just tell the journal to mark the file as not-deleted again.

At least, this all seems rather simple in my way of looking it. However
I am by no means a file system expert, so I will gladly welcome any
corrections.

-- 
Alex Malinovich
Support Free Software, delete your Windows partition TODAY!
Encrypted mail preferred. You can get my public key from any of the
pgp.net keyservers. Key ID: A6D24837

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 189 bytes --]

Re: Will Reisefs have "undo"?

[Oleg Drokin]

Hello!

On Sun, Jun 15, 2003 at 02:29:26PM -0500, Alex Malinovich wrote:

> I don't think snapshots are really needed. I would be perfectly content
> with a "semi-intelligent" filesystem that would mark files as deleted in
> the journal while leaving the file intact on the HD. As soon as the file
> has actually been overwritten, it is marked "purged" and cannot be
> recovered. But up to that point, it would be a relatively simple task to
> just tell the journal to mark the file as not-deleted again.

Hm. You seem to confuse journal with log of operations.
The journal just holds copies of the blocks we are going to overwrite
to achieve atomic block overwrite. So we cannot mark something "deleted in journal".

Bye,
    Oleg

Re: Will Reisefs have "undo"?

[Hans Reiser]

Undo should be done.  Windows is better than Linux in this regard.   
Sometime after the DARPA contract is completed we ought to do it, but I 
would be happy to see someone sponsor it before then.  It would be cheap 
to do.  There is a long thread in the archives on this topic, which is 
why I am brief now.....

-- 
Hans

Re: Will Reisefs have "undo"?

[Hans Reiser]

Fred -- Speed Up -- wrote:

>This is not the filesystem's work, KDE for instance has a trashcan, and you
>can bind the rm command to a special mv one that moves files from the
>initial place to a backup folder, the files of which you can empty regulary
>with a cron script depending on the file's "age". It's simple to implement,
>and really not something Reiser4 should be capable of ... instead
>journalising works very well to protect data from being erased, that's the
>only purpose of a modern filesystem.
>
>Fred
>
>----- Original Message ----- 
>From: "Joachim Zobel" <nc-zobeljo@netcologne.de>
>To: "ReiserFS List" <reiserfs-list@namesys.com>
>Sent: Saturday, June 14, 2003 8:38 PM
>Subject: Will Reisefs have "undo"?
>
>
>  
>
>>Hi.
>>
>>Are there any plans to add undo capabilities to reiserfs? Most modern
>>desktops have a trash can. Am I the only one who has idea that this is a
>>crappy workaround for something that should be in the filesystem.
>>
>>I am aware that this is not easy, but nearly everybody has had moments
>>where he would have loved it. And disk space is cheap, there is rarely
>>the need to overwrite anything.
>>
>>Sincerely,
>>Joachim
>>
>>-- 
>>"... ein Geschlecht erfinderischer Zwerge, die fuer alles gemietet werden
>>koennen."                            - Bertolt Brecht - Leben des Galilei
>>
>>
>>    
>>
>
>
>
>  
>
I have never used the trashcan on Linux, and probably will always remove 
most objects using rm not click and drag.  Only the FS can monitor disk 
space usage and empty the trash in response to running low on space.

-- 
Hans