Hard disk woes

[Michael Abbott]

Isn't this on topic for freebsd-users?  I remember earlier grumbles about 
lack of activity on the list, so I think it might be nice to do this 
conversation on list!

On Mon, 5 Sep 2005, Lee Brotherston wrote:

> On 4/9/2005, "Michael Abbott" <michael at araneidae.co.uk> wrote:
>
>> 2.  Goodness me, FreeBSD froze!  I know it's a hardware failure, but
>> still: it's on a auxillary ATA controller with no system files attached.
>> Is this problem of general interest?  It's certainly a massive hint to me
>> not to consider (parallel) ATA for RAID!
>
> I suspect it's a similar reason to why it would (I presume I should use 
> the past tense anyway, I've not tried it in a while) freeze when you 
> mounted a floppy disk and pulled it out of the drive without properly 
> unmounting it first.
Eww.  I hope that's past tense!

>  I suspect something that can be coded around fairly easily (for someone 
> that understands hardware drivers anyway), just that no one has got 
> around to doing it yet.
Hmm.  Seems fairly serious to me: it's definitely a stability issue, and 
the real virtue of FreeBSD is that it just doesn't crash.  (At least, 
except for the troubles that this disk has caused, that's been my 
experience.)

>> 3.  Any thoughts on what is wrong with the hard disk in question?
>
> When I had trouble like this it turned out to be a problem in the UDMA
> settings.  Somewhere in the FreeBSD->Controller->Disk chain something
> didn't like going at full whack.  I fiddled with atacontrol(8) and
> changed UDMA versions and tried PIO too, and found that tuning this down
> made everything happy.  I suspect it's something silly like the OS is
> inadvertently trying to get the drive to do something outside of it's
> specs (like get UDMA6 performance from a UDMA5 drive).

Hmm.  I'll have to play.  See, for example, if `atacontrol reinit` works. 
Here's what 'cap' has to say:

$ sudo atacontrol cap ata3 0
ATA channel 3, Master, device ad6:

ATA/ATAPI revision    5
device model          ST380021A
serial number         3HV0MYL9
firmware revision     3.10
cylinders             16383
heads                 16
sectors/track         63
lba supported         156301488 sectors
lba48 not supported 
dma supported
overlap not supported

Feature                      Support  Enable    Value   Vendor
write cache                    yes	yes
read ahead                     yes	yes
dma queued                     no	no	0/00
SMART                          yes	no
microcode download             yes	yes
security                       yes	no
power management               yes	yes
advanced power management      no	no	65278/FEFE
automatic acoustic management  yes	yes	128/80	128/80
$

Doesn't mean a whole lot to me, I must confess :(