dd problem
charlie derr
cderr at simons-rock.edu
Wed Jan 13 21:59:21 UTC 2010
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
>> ubuntu-users at lists.ubuntu.com
>> Modify settings or unsubscribe at:
>> https://lists.ubuntu.com/mailman/listinfo/ubuntu-users
>>
>
>
More information about the ubuntu-users
mailing list