Re: [Bug-ddrescue] Question about reported errorsize

[Tom Williams]

Thanks for the tip.  :) 

I used Alt-F2 to open a new console and was able to look at the kernel
log.  As expected, there are a TON of errors reading the "problem"
drive.  I'm seeing errors with "STATUS {DRDY ERR}" and failed command
"READ DMA" in the log.  The end of the log has messages that read
"Buffer I/O error on device sda, logical block {nnnnn}"

The "problem" drive is connected to my computer internally and the drive
I'm trying to rescue to is an external USB drive.

I'm planning on letting it run to see what happens. :)

Thanks!

Peace...

Tom

On 12/06/2011 11:28 AM, andrew zajac wrote:
> Hi Tom.
>
> That's a good question.
>
> First off, I like to see what's going on while I read a faulty drive.  In 
> another console, I usually run something like:
> tail -f /var/log/kernel
>
> and that shows me what the kernel sees - I pay attention to devices dropping 
> offline.  In this case, I would wonder if the drive went offline but the 
> kernel didn't notice.  This happens sometimes when the kernel can see the 
> drive controller even if there is no drive attached, as with some USB-SATA 
> connections.
>
> That being said, I like those kinds of interfaces because you can hotplug the 
> drive and potentially bring it back online without power cycling it.
>
> I would run Gnu ddrescue in the same way, but I would use a log.  That way, 
> you can stop and resume the recover.  I regularly have to physically unplug 
> and plug back in the USB connector to a drive that has dropped out like that. 
>  I find some drives tend to faint easily at high speeds, which makes the 
> slower USB speeds an asset in these cases.  Using -D or -d switches can also 
> slow things down and regulate speed in a useful way.
>   
> Good luck.
>
> Andrew Zajac
> AndrewZajac.ca
> Ubuntu-Rescue-Remix.org
>
>
>
>
> --- On Tue, 12/6/11, Tom Williams <address@hidden> wrote:
>
>> From: Tom Williams <address@hidden>
>> Subject: [Bug-ddrescue] Question about reported errorsize
>> To: address@hidden
>> Received: Tuesday, December 6, 2011, 12:26 PM
>> I'm running ddrescue from a Trinity
>> Rescue CD (3.4-bld-372) on a 500GB
>> hard drive with two NTFS partitions on it.  The hard
>> drive is dying and
>> I'm hoping to move the data to a new hard drive so it can
>> be saved.
>>
>> I've issued his command:
>>
>> ddrescue /dev/sda /dev/sdb
>>
>> and the process is underway now.
>>
>> ddrescue has reported only ONE error and the errorsize is
>> 500GB.  It has
>> 51MB of data and is in the "splitting" phase now. It looks
>> as if it's
>> going to try to split the 500GB of "errors" reported in
>> "errorsize".
>>
>> My question:  does the fact that 500GB was reported as
>> the errorsize
>> mean this process is most likely going to fail?  Is it
>> worth spending
>> the time to go through the "splitting" phase?
>>
>> I believe I'm running ddrescue 1.14, but I'm not sure.
>>
>> Thanks!
>>
>> Peace...
>>
>> Tom
>>
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