Re: Faulty drive data recovery

[Tejun Heo <tj@kernel.org>]

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?

-- 
tejun