dd problem

Karl F. Larsen klarsen1 at gmail.com
Wed Jan 13 22:32:15 UTC 2010


charlie derr wrote:
> Pedantically correcting myself.  First off I was responding directly to Karl F. Larsen (which makes it pretty ironic 
> that I started out complaining about Karl's quoting error when my mailer ended up not doing it write either :-\)
> 
> 
> charlie derr wrote:
>>> charlie derr wrote:
>>>> Karl F. Larsen wrote:
>>>>> Georg von Zengen wrote:
>>>>>> so you have to delete it, chose another name or creating a new file in
>>>>>> "nita". dd can only write into files e.g.
>>>>>> sudo dd if=/dev/sdb1 of=/media/disk/nita/sdb1 bs=2048 conv=notrunc
>> OK, first problem, you appear to have quoted me, but you've snipped out
>> all of what I typed (and a lot of other important stuff).  For instance
>> what you typed.  Which is that you didn't believe that command was going
>> to work.  So why respond to it this way?  Sorry but it's hard to
>> communicate with you no matter how hard I want to succeed at it.
>>
>>> 	Now a couple of what happened problems. Again this is on
>>> Ubuntu 9.04 using a 160 GB portable HD in a box made by ADS
>>> Tecnologies, China.
>>>
>>> 	My first question is: Why does dd ruin a file system when it
>>> is directed to put some files on the HD?
>> Because you ignored the advice above and fumbled around trying things
>> instead.  If you'd actually executed the command Georg suggested (at the
>> time Georg suggested) it would have worked as expected.
>>
>>> The HD had ext3 file
>>> system and it was shown as /media/disk then. Then I used dd to
>>> get as much as possible from a bad HD and put it on the
>>> portable HD. It did but it ruined my portable system! Now when
>>> plugged into this computer it showed as /media/CEE.
>>>
>> It's all about you gaining an understanding of the difference between
>> partitions and filesystems and how things that live at /dev can be either
>> (it's up to the intelligence and knowledge of the user to distinguish
>> sometimes).
> 
> This is the part I wanted to make sure I corrected.  What I wanted to say was "the difference between disks and 
> partitions"  (not partitions and filesystems)  The error Karl was not understanding that when you thought you were 
> writing to a file on a particular partition, you were instead writing your image to *the entire portable harddrive* 
> (because that's what you told dd to do).
> 
> 
> 
>>> 	After getting the stuff on another computer I tried to fix
>>> the portable. I tried to remove CEE. I did remove most of it
>>> but not all. Took the HD out of the portable and onto this
>>> computer. Here I used Partition Editor to see this HD. It said
>>> the HD has a ntsf file system and no sign of any ext3.
>> This totally makes sense to me.  In the reply you snipped I already
>> explained that you had made an exact copy of your computer.  Obviously
>> that computer had an NTFS filesystem on it.  Now it's on your portable
>> (and that's all that's on the portable because you told dd to overwrite
>> everything else the way you executed your command.
> 
> This was only temporally accurate (in terms of my use of "Now..." ) until the below effort (wiping it clean again and 
> replacing the NTFS filesystem with an ext3 one).
> 
>>> To fix
>>> this I had to delete the partition and then re-make a new ext3
>>> file system.
>>>
>>> 	Another question. I backed up all of /home/karl which is now
>>> about 25GB with dd. It worked fine and when complete I looked
>>> at /media/disk and ls and ls-al both said there is nothing on
>>> the portable HD!  I unmounted the portable and turned it off,
>>> and then back on. Looked and sure enough the backup was on the
>>> portable as I expected! Why didn't it show up right after dd
>>> was complete?
>> I don't know the answer to that one.  Maybe someone else has a clue.
>>
>>     be well,
>>          ~c
>>
>>
>>> 73 Karl
>>>
> 
> Sorry for the errors in what I posted quickly an hour or so ago.
>       ~c
> 
> 
> 
>>> --
>>>
>>> 	Karl F. Larsen, AKA K5DI
>>> 	Linux User
>>> 	#450462   http://counter.li.org.
>>>          Key ID = 3951B48D
>>>
>>>
>>> --
>>> ubuntu-users mailing list
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>>>
>>
> 
> 
	If it is ok I will just have to say your words do not explain 
much to me.

73 Karl


-- 

	Karl F. Larsen, AKA K5DI
	Linux User
	#450462   http://counter.li.org.
         Key ID = 3951B48D





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