Re: Faulty drive data recovery

[Atila <atila.alr@dpf.gov.br>]

Em 26/11/2010 15:29, Tejun Heo escreveu:
> Hello,
>
> On 11/24/2010 06:00 PM, Greg Freemyer wrote:
>>>>> HI, I'm trying to recover data from a damaged hard disk, which has
>>>>> plenty of bad sectors, but also has many good ones. The problem is that
>>>>> when a bad sector is found, the drive keeps trying to read it, instead
>>>>> of giving up and just move on, so the average data read rate is around
>>>>> 5Kb/s. With such rates, it will take more than an year to finish. Since
>>>>> I'm using gnu ddrescue (which logs bad sectors, so one can try then
>>>>> again later), my goal is not waste time with errors, leaving the retries
>>>>> to a second round.
>>>>> So, my first attempt was to drastically lower the timeouts in
>>>>> libata-eh.c. It seems to have improved a little, but I'm not having more
>>>>> than 12Kb/s.
>>>>> Is there any way to minimize retries and make errors finish faster?
> You can directly issue r/w commands using SGIO where you can control
> retry and timeout explicitly.  Hmm... it might be a good idea to allow
> userland to set FAILFAST bit on a block device?

Sounds like a great idea to me. I think it would become popular in
forensics.

I followed Artem Bokhan s' tip on timeout and tried Greg Freemyer s' on
smartctl. Unfortunately this particular drive is only ATA-7, so scterc
wasn't available. But is definitively good to know.

I never played with SGIO before, but there is plenty of time to learn to
use it before ddrescue can finish copying.:)

Thank you all,

Atila