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>
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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 > >
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