sda2 is corrupted

[Jim]

On 07/06/2012 12:35 PM, Reindl Harald wrote:
>
> Am 06.07.2012 18:28, schrieb Jim:
>> On 07/06/2012 12:11 PM, Jim wrote:
>>> On 07/06/2012 12:02 PM, Michael Schwendt wrote:
>>>> On Fri, 06 Jul 2012 11:22:55 -0400, Jim wrote:
>>>>
>>>>>>> /dev/sdb1 is now a blockwise copy of /dev/sda2
>>>>>> 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 .
>>>> That makes no sense. If /dev/sdb1 points at a corrupted filesystem,
>>>> above "dd" command will copy the same corrupted filesystem to /dev/sda2.
>>>> That's expected and okay, if you only want to keep that one read-only as
>>>> a backup of the originally corrupted filesystem. Then you can play with
>>>> rescueing sdb1 - but be careful and remember that sda2 is supposed to be
>>>> your backup of a corrupted filesystem. Don't mess with that one.
>>>>
>>>> Better would have been to copy sdb1 to an image file instead of another
>>>> partition device.
>>>>
>>> sda2 is the corrupted file system.
>>> I'm trying to send a img of the sda2 to backup hard drive sdb1 .
>>> I' running into a read-only filisystem on sda3 , but :
>>>
>>> # mount | grep sda3
>>>
>>> /dev/sda3 on / type ext4 (rw,relatime,seclabel,data=ordered)
>>>
>>> it say it is rw but when i run the dd command i get a read-only filesystem.
>> mount | grep sdb1
>> /dev/sdb1 on /media/backup type ext4 (ro,relatime,seclabel,errors=continue,data=ordered)
>>
>>
>> now I find out that sdb1 ,external/USB hard drive is read-only, what command would I use to make it a read-write
>> partition.
> boag this is the result of "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"
>
> as i said in my first reply today
>
>>> 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
> so you have to create a NEW fileystem on /dev/sdb1
> you have overwritten it with the source-partition of you dd-command
>
> also you did not realize why we are suggested to use dd or ddrescue
> before any other attempt - because you get a BLOCKWISE image of the whole
> partitionor even disk which can be backuped mutilple times to test restore
> strategies
>
> but if you are start using dd the wrong way you are pretty soon at the end
> try to undersatnd what commands are supposed to do and read their manpages
> CAREFULLY before use them, use google to learn about them and AFTER that
> think if you are really sure to be the right person for data-restore
> on a damaged disk
>
> BUT even if you are coming to the conslusion you are the wrong one
> the FIRST step to make CAREFUL a dd-image of a appearently dying
> FS/disk is the right way becasue if the disk is dead whoever can continue
> try to restore data from this image
>
>
>
>
>
Believe me Reindl I been very much aware about writing on sda2 .

And thank you for your help

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