Re: SATA hdd refuses to reallocate a sector?

[Mark Lord <mlord@pobox.com>]

On 13-06-24 03:14 AM, Ondrej Zary wrote:
..
> Being tired of using hdparm manually, I created a simple hdd_realloc utility
> that reads the disk in big blocks (1 MB). When there's a read error, it reads
> the failed block sector-by-sector and tries to rewrite the sectors that fail
> to read. It work fine for disks with just a couple of pending sectors.

Something like that would work very well if it used the hdparm approach
(directly to the drive) for the sector-by-sector part.

Going through the block layer isn't always going to work,
because the kernel likes to do I/O in PAGE_SIZE multiples.

And the SCSI stack in Linux has rather atrocious error handling.
It lumps multiple requests together, and can fail the entire lot even
if only a single sector is bad.

Cheers
-- 
Mark Lord
Real-Time Remedies Inc.
mlord@pobox.com