On Wednesday 29 September 2004 10:28, Vincent wrote:
> Hello,
> a friend of mine gave me a defectuous hard drive just to see what I
> could make of it under Unix. The nasty thing is that I suspect the
> controler, not the disk, to be damaged. Anyhow.
>
> I make a disklabel+newfs okay, try to copy a large file to pin the
> problem, and the cp (or the fsck I did after) hangs up on :
>
> wd1: transfer error, downgrading to Ultra-DMA mode 1
> wd1(piixide0:1:0): using PIO mode 4, Ultra-DMA mode 1 (using DMA data
> transfers)
> wd1e: error reading fsbn 756960 of 756960-757087 (wd1 bn 757023; cn 751
> tn 0 sn 15), retrying
> wd1: (uncorrectable data error)
>
> Thereafter nothing happens, fsck_ffs seems to be blocked on physio,
> probably in the driver.

There are conditions under which an ATA disk will simply stop responding to 
any commands.  The driver should notice this and start timing them out, 
though.  How long did you wait?