[ale] recovering an ext3 drive

[Geoffrey]

I'll say up front that I think that undelete tools are terribly valuable 
and it would be nice to have one for ext3.  That being said...

Michael D. Hirsch wrote:
> I'm sorry, but I've rarely read a post in which I disagreed with nearly 
> every sentence as vehemently as this one.
> 
> On Monday 20 January 2003 02:34 pm, Geoffrey wrote:
> 
>>Well I still disagree.  If you choose a program called 'remove' or
>>'delete' or any thing in the vernacular, then by damn understand what
>>you're about to do.
> 
> 
> Why?  All I want is to get rid of it.  Or maybe I'm using another program
> that removed the file without me knowing it was going to do that.  Why 
> should I have to understand the inner guts of every program I use, all I 
> want is my file back.  By your reasoning you'd agree with having an  
> undelete command if the "rm" command were renamed 
> "movethefilesomewhereelsesoidonthavetothinkaboutitanymore".  (In UNIX 
> tradition we could name the command mvtflsmwrlssidnhvtthkbttnymr.)

I didn't say you should understand the inner guts of every program you 
use.  You should certainly understand HOW to use it and WHAT it does.

 From the man page:

'rm removes each specified file'

How much clearer must it be.  Maybe we should change it to rmk (remove, 
kinda).

> 
> 
>>We all have accidents, but you can't stop everything.  You've got to use
>>some common sense.
> 
> 
> That's silly.  Since you can't stop everything, you are arguing to stop 
> nothing.  

No, I'm saying there's a happy medium.

> 
> I say that whenever practical computers should "do what I mean".

Well you better build one hell of a AI machine, because 'do what I mean' 
varys quite substantially.  So, would you you like the brakes in your 
car to stop you completely, or slow you down a bit, or hey, maybe it 
should 'break' the axle.  After all, that's what I meant for it to do.

"do what I mean" is impossible, and quite dangerous.

> Typically 
> when someone removes (tenchincally, unlinks) a file all they really wanted 
> to do was to get the file out of the way so that it would not interfere 
> with whatever they are doing.  When I throw things out I rarely pass them 
> through a shredder, why should a computer be so different? >

Just the same, I don't intend on dragging out of the garbage either. 
That particular example is not very good either.  Say you throw a check 
in the garbage.  Much like the file system, if you get it back quick you 
might be okay, then again if you wait too late, it's covered in tomato 
sauce and illegible.  The fact that you did not shred it, is not really 
a valid comparison.  Further, what you throw away sits around for a 
while because the garbage goes out once a week.  I assure you, the 
reason for that is not so that you might retrieve that winning loto you 
chunked, but just a matter of how often it's necessary to haul the trash 
off.

> 
>>If the expectation is that you must protect the fool from himself all
>>the time, systems will get so bogged down with dealing with the loose
>>screw behind the keyboard, they won't do anything useful.  Think about
>>it.  The ideal solution is, you remove a file.  What REALLY happens is,
>>it's copied to a safe place that' not touched.  Just in case the machine
>>might crash, it's also copied to a tape.  Incrementally to the tape, one
>>file at a time as they are deleted.  What's wrong with this picture???
> 
> 
> But no one is saying to prevent everything, just common mistakes.  I think 
> everyone on this list has accidentally deleted a file--maybe even an 
> important file.  If there is a clear solution that would save people lots 
> of angst, why not do it?  Yes, there will still be corner cases it might 
> not catch--so what?  

The solution is backing up the files properly.  People need to 
understand that removing a file means just that.  If you don't like it, 
then create an alias where remove pushes the file off somewhere.

I don't understand why people want a command to 'kinda' do what it's 
supposed to do.  rm - remove, what's so hard about that???

Now, understand, I'm not against people creating tools to retrieve files 
that are accidentally removed.  I've used them, I think they're great. 
But for someone to say, Linux sucks cause I removed a file and now I 
can't get it back.  What's with that?

Damn, the chainsaw said DANGER, but I cut my foot off anyway.

> 
> 
>>Do people get behind the wheel of a car without learning to drive? No.
> 
> 
> Wanna bet?  They most certainly do.  And even the ones that do learn to 
> drive don't become a professional driver.  You are asking (no, telling) 
> everyone that they should use a computer with a professional attitude.  
> That is just wrong.  Computers should be for everyone, not just the elite 
> few.

No, I'm not.  I'm saying, don't slur the meaning of a command, then 
bitch about it doing what it was damn well designed to do.

There are protections in place to protect the non-professional in 
computer environments.  Virtually all the latest gui desktops have some 
variation of the 'recycle bin.'

I agree that computers should be for everyone, but you should get some 
training and understand the device before you use it.  It's all a matter 
of how valuable it is to you.  I knew a guy who went out and bought a 
brand new lawn tractor.  Cranked it up, drove it about 2 feet and 
trashed it because he didn't put oil in it.  So who's at fault?  RTFM.

I'm not an auto mechanic, but I check the fluids in all my vehicles on a 
regular basis.

> 
> 
>>Why aren't all cars encased in big soft bubbles, so that there's no such
>>thing as an accident?
> 
> 
> But by your argument we wouldn't have cars with seat belts, roll bars, or 
> crush zones.  "If you drive a car into another car, you must have wanted 
> it to kill you."

Again, there's a balance here.

> 
> Everyone should go and read "The Inmates are Running the Asylum" to learn 
> just how far our engineer ideas of a good interface are from the real 
> world.  This is a classic case of the problem.
> 
> Given the incredible speed and storage of modern computers, I find it hard 
> to believe that one couldn't design a decent filesystem that would have 
> the kind of properties which would make users happy.  Journaling is a good 
> start, but undelete is probably just as important, if not more so.
> 
> The basic rule should be, when an inode is unlinked, it and its disk blocks 
> get moved to a MRU (Most Recently Used) list.  When someone needs to 
> relink (a new syscall?) the MRU can be consulted.  To keep the engineers 
> happy, the MRU could be limited to some reasonable percentage of the file 
> system, or maybe for performance freaks, to a percentage of the unused 
> space.  Or, if the designer felt like getting fancy, some kind of decay 
> functions so that it attempts to keep all files around for an hour, but 
> after that it starts deleting files according to some rule.

So you're saying that you don't want the file to be removed immediately, 
just some, unspecified time in the future.  Unspecified, because all 
user's needs and wants are different.

So the file is removed 6 days, 2 hours, 5 minutes, 38 seconds later, and 
damn, I decided that I wanted it 6 days 2 hours 5 minutes and 45 minutes 
later.  Now where is it?  This system is really screwed up cause I could 
get the file back last week, but not this week.

> 
> I imagine this at the filesystem level, not by putting wrappers around 
> "rm".  It shouldn't matter who does the unlinking, the filesystem should 
> just keep track.

Wrong.  The user should be trained to use an archival device if they 
think they might want that file back.  rm is remove.  I don't see why 
you want to cloud the purpose of the program.

> 
> (I'm imagining this as open source, so if you want to file off this safety 
> device, you can get a filesystem that will let you shoot yourself in the 
> foot.)
> 
> If ext3 had this, everyone would have this capability and few would know 
> about it.  Someone like you who never made a mistake would never know it 
> was there.  Neither would ordinary users know--all they would know is that 
> undelete works.
> 
> --Michael
> 

-- 
Until later: Geoffrey		esoteric at 3times25.net

The latest, most widespread virus?  Microsoft end user agreement.
Think about it...

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