Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 26 Oct 2009 04:20:38 -0600
From:      Warner Losh <imp@bsdimp.com>
To:        Hans Petter Selasky <hselasky@c2i.net>
Cc:        "hackers@FreeBSD.org" <hackers@FreeBSD.org>, "non@ever.sanda.gr.jp" <non@ever.sanda.gr.jp>, "freebsd-usb@FreeBSD.org" <freebsd-usb@FreeBSD.org>
Subject:   Re: Help troubleshooting...
Message-ID:  <96830A33-8392-4C05-B073-48026E24C895@bsdimp.com>
In-Reply-To: <200910260959.20772.hselasky@c2i.net>
References:  <20091025.133437.-1844000782.imp@bsdimp.com> <4AE4E7AF.8060103@ever.sanda.gr.jp> <200910260959.20772.hselasky@c2i.net>

next in thread | previous in thread | raw e-mail | index | archive | help
But there was no indication the device went missing on the console.  
And it wasn't until I unplugged it that da0 detached. Usually in the  
past when it has started throwing errors the console was chatty about  
why.

Warner


On Oct 26, 2009, at 2:59 AM, Hans Petter Selasky <hselasky@c2i.net>  
wrote:

> On Monday 26 October 2009 01:05:03 non@ever.sanda.gr.jp wrote:
>> M. Warner Losh wrote:
>>> I have a usb stick (8GB) on it.  This stick has about 5GB of junk on
>>> it at this point.
>>>
>>> I tried to do 'cat * > /dev/null' recently, to measure how fast it
>>> goes.  It got about 1GB into the drive and then I got device missing
>>> messages.
>>>
>>> So devfs thinks the device went missing:
>>
>> Warner-san, maybe it is caused by the hardware problem on the USB  
>> flash
>> memory. Some chip on the memory might have too much heat when you  
>> access
>> the memory at fast rate. Then it stops working.
>>
>
> What happens if you read from two USB disks at the same time?
>
> If the device went missing the USB HUB signalled that. This is maybe  
> an
> indication that the USB firmware on the device crashed. Maybe this  
> is due to
> heat, or unhandled race conditions when the load goes high.
>
> Try using "dd" and vary the block size from 512 to 65536 bytes. Does  
> it stop
> working with all block sizes over time?
>
> --HPS
>
>



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?96830A33-8392-4C05-B073-48026E24C895>