[ydl-gen] prob mounting an external fw ext2 partition

[Derick Centeno]

Greetings:
Due to the issues of language translation I'd like to recommend one 
popular tool which many have found useful in the past.  However, I 
cannot say how well translations into French will be.  Test the 
application with a few phrases you know well.  There are other language 
translators however, this is the one I have used most.  For the 
languages I have used it to translate; it is not a scholar's tool but 
it will provide at least a basic and reliable idea of what is being 
discussed.

http://babelfish.altavista.com

Ok.  Now that is out of the way.  There are two links I hope you will 
consider reviewing which discuss in detail the differences (complete 
with reference links) between the BSD version of pdisk, the Linux 
version of pdisk and Apple's Disk Utility/Partition program.  The 
nuances are important.  The references in these pages may explain some 
of the errors you are seeing and clarify further limitations in using 
one tool versus another for partitioning purposes.

http://www.netbsd.org/Ports/macppc/partitioning.html

http://www.hmug.org/man/8/pdisk.php

The installation guide for YDL 4.0 discussing partitioning is found 
here:

http://www.terrasoftsolutions.com/support/installation/

In the Terra Soft Solutions guide you will notice that the 
recommendation is to create partitions from Apple's Disk Utility 
program and create Unallocated (which is read by Disk Druid as Free 
Space), first.  However, all this information as hair splitting as it 
may be may not be actually useful to you because of how you are 
choosing to implement a backup.

You state that "the purpose of this extra partition is to backup all of 
my /home."  Perhaps the best way to present the problem in an 
understandable light (by way of analogy) is to consider a table or desk 
with a few locations or levels in which to place certain items which 
will be used daily ... say paper, pencils, paper clips -- other odds 
and ends of a place where some thinking and work is done.  Now as long 
as the entire structure of the desk is physically intact and 
functional, all the other items remain in their respective places in 
the order one has chosen.

However, suppose something upsets that physical order... a leg breaks, 
a slot doesn't close, the floor is at an angle ... now that same 
environment is not as useful.  The integrity and nature of one's work 
at that desk cannot progress as before and attention must be redirected 
away from the actual process of one's preferred work.  One must look 
for another location or temporary work space or/and replace the desk 
altogether or rebuild the floor or whatever.

Let's return to the reality of what a hard disk is and what partitions 
are actually comprised of.

A hard disk is a device which utilizes electricity (which 
simultaneously itself distributes a minute magnetic charge) so that 
areas along each platter within the hard disk are magnetically marked 
as containing data which begins at one location and ends elsewhere.  
Consider that all such markers of data, as well as the data itself is 
comprised of magnetic signatures of one sort or another.

If you recall basic physics from childhood or even high school or 
perhaps you would consider participating with a local computer users 
group to discuss this subject as a question to consider for deeper 
understanding -- all magnetic/electrical systems are extremely 
sensitive to minute changes ranging from muons/nutrinos shooting to 
Earth from the Sun (Sunspots) which interfere with all electronics, to 
minute changes in the Earth's gravity, to someone -- a child placing a 
magnet or toy containing magnets (like a magnetic checker/chess board) 
on your desk -- any of these (or other) things can affect your computer 
and your hard drive.  Remember also that the magnetic signature 
isolating one region of data from other is very tiny and easily changed 
by any of these or any very weak magnetic or electrical charges -- 
which exist in nature and natural human social environment.

Although the electronics have improved, certain laws of physics remain 
unchangeable within current human knowledge and so other means of 
protecting data are utilized by professionals as a means of protecting 
data on a hard drive.  A few of these means are available for use by 
non-professionals, if the non-professional is aware of the nature of 
how fragile data actually is.  One basic rule easily applied, is never 
store important data which one needs as a backup -- as a partition on 
the same hard drive -- or any hard drive.  Utilize instead a reliable 
technology such as rewriteable CDs and burn your data to be preserved 
to that CD media.  CDs can be ruined yes, by temperature variations and 
exposure to direct sunlight, but if the CDs are kept in a closed and 
dry environment the backup data burned onto to them will remain 
unchanged as the data record is physical -- not magnetic.

Means of storing data from one partition to another on the same or even 
to another hard drive -- is a gamble.  A gamble which physics has 
already determined is a "losing hand" -- to use an American expression 
usually used in Poker, the card game.  Storing data in the short term 
onto magnetic media also is not a wonderful solution, but if that media 
is not near one's daily work area -- then no matter what happens to the 
desk or the main hard disk one is working with -- the stored data will 
survive because it is physically somewhere else and yet readily 
retrieveable.

If the general idea is clear, then the next step is developing and 
maintaining a personal and steady backup and recovery strategy.  A 
variety of local computer user groups explore issues and concepts 
covered here from time to time as a matter of standard practice; at 
least they should.  If not, I'm sure you can find discussions regarding 
this and related topics on the net.  If your data is important to you 
in any sense, then so the concepts discussed briefly here should be.

Best wishes....

On Dec 5, 2005, at 6:22 AM, Une bévue wrote:

>
> Hey all,
>
> i have an external firewire with, for the time being, three partitions 
> :
>
> hfs+ (i don't want to see it from ydl)
> fat32 (allready ok)
> ext2 done under mac os x using pdisk
>
> pdisk line related to the latest :
> 10:     Apple_UNIX_SVR2 bup                   21223792 @ 2224808   ( 
> 10.1G) S2  UFS k0  /usr
>
> /etc/fstab :
> /dev/sdb10              /mnt/bup                ext2    
> defaults,noauto        $
>
>
> when i want to mount this partition i get the following error message :
> $ sudo mount -t ext2 /dev/sdb10 /mnt/bup
> mount: type de sys. de fichiers erroné, option erronée, super bloc 
> erroné
> sur /dev/sdb10,
>        ou trop de systèmes de fichiers montés
>
> (too much fs mounted,  erroneous fs,  erroneous super block)
>
> also i'm unable to find pdisk on my ydl 4.0.1 even if yum says it's 
> allready installed.
>
> what is the formatting utility within ydl ?
>
> because i want to change this  /dev/sdb10 from ext2 to ext3
>
> the purpose of this extra partition is to backup all of my /home.
>
> best,
>
> une bévue
> -- 
> Une bévue
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