System lockups caused by USB external HDD

[CDP]

On 01/24/11 11:34, Hans Petter Selasky wrote:
> On Monday 24 January 2011 10:00:53 CDP wrote:
>> On 01/24/11 01:56, Daniel O'Connor wrote:
>>> On 24/01/2011, at 9:10, CDP wrote:
>>>> g_vfs_done():da0s2[WRITE(offset=xxxxxxxxxxxx, length=16384)]error = 5
>>>> [several more lines similar to the above]
>>>> panic: softdep_move_dependencies: need merge code
>>>> cpuid = 0
>>>> KDB: stack backtrace:
>>>> #0 0x... at kdb_backtrace+0x5e
>>>> #1 0x... at panic+0x182
>>>
>>> It looks like the disk is dying, or the FS is corrupt (the former might
>>> cause the later).
>>>
>>> Can you run smartctl on the disk? Unfortunately a lot of enclosures
>>> reject SMART commands so you might not be able to :(
>>
>> I have attached the output of smartctl -d sat -a /dev/da0. I didn't yet
>> run a SMART long test for the simple reason that the disk is going into
>> sleep mode and interrupts it. Haven't bothered to keep it alive for a
>> long test but I might just do that.
>>
>> Although, I doubt it's a disk failure, since I do backups on it without
>> problems by using FreeBSD 7.3, on the same space where FreeBSD 8.x
>> fails. And I am talking about over 150GB of data in one run, while
>> 8.2-RC2 crashes after 5-10GB. I have experienced disk failure in the
>> past, on SATA, and a few read/write errors never caused a system lockup.
>>
>> My feeling is that enough traffic on USB causes the problem, and that
>> this problem is only present in the new USB stack.
>> Unfortunately downgrading to 7.x is not an option because there are
>> things that won't work on this notebook.
> 
> If you run a simple test like this:
> 
> dd if=/dev/da0 of=/dev/null bs=65536
> dd if=/dev/da0 of=/dev/null bs=16384
> 
> Do you then see any errors?
> 
> Do you have a spare USB memory stick which you could run similar write tests 
> on?


Both reads fail with I/O error, while writes to an unused partition seem
to be fine (I interrupted the writes after a while):

% dd if=/dev/da0 of=/dev/null bs=65536
dd: /dev/da0: Input/output error
191732+0 records in
191732+0 records out
12565348352 bytes transferred in 429.999272 secs (29221790 bytes/sec)

% dd if=/dev/da0 of=/dev/null bs=16384
dd: /dev/da0: Input/output error
126427+0 records in
126427+0 records out
2071379968 bytes transferred in 169.431766 secs (12225452 bytes/sec)

# dd if=/dev/random of=/dev/da0s3 bs=65536
^C329378+0 records in
329377+0 records out
21586051072 bytes transferred in 1003.020293 secs (21521051 bytes/sec)

# dd if=/dev/random of=/dev/da0s3 bs=16384
^C679571+0 records in
679571+0 records out
11134091264 bytes transferred in 690.135793 secs (16133189 bytes/sec)

This is what I get in /var/log/messages when the I/O error occurs:
(da0:umass-sim0:0:0:0): AutoSense failed

However, I experience no lockup. Maybe this situation is not handled
correctly at another level ?

I've done the read test with a 4GB memory stick and it passed. I'll do
the read tests with another HDD later today, but I expect to get the
same error, since on file copying it behaves in the same way.

Claudiu.