[vox-tech] mystery error when connecting USB HD

[David Rosenstrauch]

Dylan Beaudette wrote:
> Hi.
> 
> Recently upgraded my kernel and noticed the following message when connecting 
> an external USB HD:
> 
> 
> [111490.755865] attempt to access beyond end of device
> [111490.755865] sdc: rw=0, want=586072369, limit=586072368
> 
> With the the previous kernel it just read:
> 
> Buffer I/O error on device sdc2
> 
> Any ideas on how this may have happened or how to fix this?
> 
> Thanks,
> 
> Dylan

Funny you should ask this.  I just ran into this exact situation 2 days 
ago, and so (assuming you're running into the same issue that I did) I 
know the problem - and solution - pretty intimately.

I was setting up a new server, and was moving the old (IDE) hard drive 
from the old server to the new one.  And all of a sudden the new server 
started barfing those messages on the drive, when I never had any 
problems with the drive in the old server.

Turns out the issue was something called an HPA - a Host Protected Area 
- on the drive.  (See here for more details: 
http://en.wikipedia.org/wiki/Host_Protected_Area).  The new server was 
not recognizing and reading the HPA, and so it looked to the OS like the 
disk was smaller than it is.  Hence all the error messages.

The cause for me was that the old server was loading and using ide 
interface kernel modules (e.g., piix.ko) for accessing the drive, while 
the new server was using only sata modules (e.g., sd_mod.ko).  For some 
reason the sata module wasn't recognizing the HPA.

Once I identified the problem, and had the new server load its 
appropriate IDE module (amd74xx.ko) everything worked fine again.  Now 
that I'm using the IDE module, the server now spits out an appropriate 
message during boot (i.e., to dmesg) informing me about the HPA:

hdb: Host Protected Area detected.
         current capacity is 234375000 sectors (120000 MB)
         native  capacity is 234441648 sectors (120034 MB)
hdb: Host Protected Area disabled.
hdb: 234441648 sectors (120034 MB) w/8192KiB Cache, CHS=65535/16/63

So try to figure out what's the appropriate IDE module for your mobo and 
load that at boot-up and the problem should go away.

HTH,

DR