Re: LSISAS1068E + WDC WD2002FYPS: I/O error & Sense Key

[Allan Wind <allan_wind@lifeintegrity.com>]

On 2009-08-03T09:34:53, James Bottomley wrote:
> On Mon, 2009-08-03 at 01:08 -0400, Allan Wind wrote:
> >
> > The above complains about sector 3907028974 which is exactly 
> > 19566 sectors greater than the size of the raid array according 
> > to parted.  In other words it appears to be an access to the last 
> > sector of the array.
> 
> If it's a read beyond the end of a partition, then it's possible it got
> rejected in the partition checking logic before ever reaching the I/O
> controller (which would explain why no messages from the fusion in the
> log).
> 
> However, I don't think the analysis is correct.  Parted says
> 
> 
> > Number  Start   End          Size         File system  Name  Flags
> >  1      34s     19565s       19532s                          bios_grub
> >  2      19566s  3907029134s  3907009569s  ext3               raid
> 
> So the absolute sector number 3907028974 is within partition 2.

I was actually trying to make a different point.  Namely that it 
was curious that the error message complains about sector
3907028974 which is exactly the size of the array + 19566, or in 
other words 1 sector past the end of array:

/dev/sdb2
start: 19566
end: 3907029134
size: 3907029134 - 19566 + 1 = 3907009568

/dev/md0
start: 0
end: 3907009407
size: 3907009407 - 0 + 1 = 3907009408

If dm maps linear to the disk sectors:

dm  /dev/sdb2
0   19566
1   19567
...
3907009406 3907028972
3907009407 3907028973

What dm sector would map to physical sector 3907028974?


/Allan
-- 
Allan Wind
Life Integrity, LLC
<http://lifeintegrity.com>