sda2 is corrupted (HOWTO NOT HELP)

[Rick Stevens]

On 07/06/2012 08:22 AM, Jim issued this missive::
> On 07/06/2012 11:09 AM, Reindl Harald wrote:
>>
>> Am 06.07.2012 17:01, schrieb Reindl Harald:
>>>
>>> Am 06.07.2012 16:11, schrieb Jim:
>>>> On 07/05/2012 01:30 PM, Reindl Harald wrote:
>>>>>> I have tried to use fedora and Gparted with no luck
>>>>> you should not play around before
>>>>> knowing what problem the drive has
>>>>>
>>>>> if it is a physical problem google for "ddrescue"
>>>>>
>>>>>> There are some important data files  I must save off of sda2
>>>>> what about BACKUPS?
>>>>>
>>>>> ff your data is important backups exists
>>>>> if your data is not important it does not matter
>>>>>
>>>>> why do people still need to learn it the hard way?
>>>>>
>>>> I run  dd if=/dev/sda2 of=/dev/sdb1  to copy, supposely a 26gb image to sdb1 but i do not see a image on  sdb1 .
>>>>
>>>> Confused ???
>>> no, just stupid because you do not read manuals nor know anything about
>>> basic-commands and that is why you destroyed /dev/sdb1 if there were
>>> data by overwrite the whole partition
>>>
>>> /dev/sdb1 is now a blockwise copy of /dev/sd1
>>>
>>> if you want a image you have to use "dd if=/deV7sda1 of=/path/filename.image"
>> well, i guess the reason why this happened was a combination
>> of plain stupid advise below without explain what it does in
>> a real dangerous way and blindly following any advise without
>> trying to understand what are you doing
>>
>> hopefully lesson learned -> BOTH of you!
>>
>> this is why i said "google for ddrescue" and NOT provide any
>> HIGH DANGEROUS command line
>>
>> -------- Original-Nachricht --------
>> Betreff: Re: sda2 is corrupted
>> Datum: Thu, 5 Jul 2012 20:15:14 +0200
>> Von: Heinz Diehl<htd at fritha.org>
>> Antwort an: Community support for Fedora users<users at lists.fedoraproject.org>
>> Organisation: private site
>> An:users at lists.fedoraproject.org
>>
>> On 05.07.2012, Jim wrote:
>>
>>> There are some important data files  I must save off of sda2
>> Before you start any rescueing, take a full snapshot of the partition,
>> e.g. "dd if=/dev/sda2 of=/dev/on_an_external_disk"
>>
>>
>>
> that is exactly what I did but nothing shows up on /dev/sdb1 external
> drive after dd has completed .

Jim, what the others are trying to say (and several of them not too 
gracefully) is that the command you ran simply did a block-for-block
copy of /dev/sda2 over the top of /dev/sdb1.  /dev/sdb1 is now an exact
copy of /dev/sda2 and whatever was on /dev/sdb1 has now been destroyed.

You need to re-create a filesystem on that /dev/sdb1 partition. Plug the
drive in and (as root) recreate the filesystem:

	mke2fs -t ext4 /dev/sdb1

When that's done, mount /dev/sdb1 somewhere (usually there's a "/mnt"
directory you can use). Example:

	mount /dev/sdb1 /mnt

Finally, you can do the copy by entering this command:

	dd if=/dev/sda2 of=/mnt/driveimage.img

This would create a file, "driveimage.img" in the "/mnt" directory (and 
thus on /dev/sdb1). Once that's complete, you can unmount /dev/sdb1:

	umount /mnt

and unplug the drive to keep it safe. When that's all done, you can
attempt to run the fsck on /dev/sda2.
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- Rick Stevens, Systems Engineer, AllDigital    ricks at alldigital.com -
- AIM/Skype: therps2        ICQ: 22643734            Yahoo: origrps2 -
-                                                                    -
-          Consciousness: that annoying time between naps.           -
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