On Tue, 27 Jul 2004, Marc Haber wrote: > > Do you mean that it's a different sector number every time you run your > > test, or a different sector number every time you put a different disk in > > the enclosure, or something else? > > The number reported in the "I/O error" line (with USB debugging turned > of) is a different one every time the test is run. Once the error is > shown, the USB subsystem seems to get into a bad state and all > subsequent requests fail.
I think that's not the USB subsystem getting into a bad state; more likely it's the SCSI subsystem taking the disk off-line because of unrecoverable errors. Unplugging the drive and then plugging it back in ought to help. > When I reboot and repeat the test, the error > repeats after different time spans (sometimes after a minute, > sometimes after multiple hours) with the same sector number. Above you said "The number reported in the "I/O error" line ... is a _different_ one every time the test is run." Here you say when you repeat the test, the error repeats with the _same_ sector number. Which is correct? "... after different time spans..." Does that mean sometimes you are able to read the sector without getting an error? > Once the > first error has appeared, the sector numbers of the subsequent errors > are all near the first one. Again, that's probably because the disk is off-line. Once that happens all further I/O requests fail, so you see a series of errors with incrementing sector numbers. > Subsequent tries with the two other disks show the first error at > different sector numbers, but always the same number for a given disk. That would be consistent with the notion of certain bit patterns confusing the USB controller. On different disks those patterns would be present in different sectors. > However, trying the same on another system, gives a different "same > number" for a given disk, That's _not_ consistent. Hmmm... > and all three disks are fine if connected > directly to the local IDE bus. This makes me think that I do _not_ > have a disk problem. I agree with you. Can you try using this device on a system running Windows? If you still get similar errors (and especially if they occur at the same sector locations) then you should try to exchange the enclosure or get it repaired. > > In the log you sent there were multiple > > errors and they _all_ referred to the _same_ sector. > > I cut the log after the first I/O error message. The next read command > is "28 00 01 1e 01 28 00 00 78 00" which fails again, this time after > 30208. That refers to the same sector number as the first error, 18743651. The calculation is: 0x011e0128 + (30208/512) = 18743592 + 59 = 18743651. You read off the 0x011e0128 from the third-sixth bytes in the command to get the starting sector, and divide the number of bytes successfully read by 512 to see how many sectors past the starting sector the error occurred. > > > I am pretty sure it's not the drive (I have tried three), but can the > > > USB adapter in the system be a problem as well? > > > > It's possible. The USB adapter just might be sensitive to certain > > patterns of data, and the sector in question might contain one of the bad > > patterns. > > This is the lspci output of my EHCI adapter: > 0000:00:0c.2 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 63) (prog-if 20 > [EHCI]) > Subsystem: VIA Technologies, Inc. USB 2.0 > Flags: bus master, medium devsel, latency 32, IRQ 9 > Memory at f4000000 (32-bit, non-prefetchable) [size=256] > Capabilities: [80] Power Management version 2 > 0000:00:0c.2 Class 0c03: 1106:3104 (rev 63) (prog-if 20) > Subsystem: 1106:3104 > Flags: bus master, medium devsel, latency 32, IRQ 9 > Memory at f4000000 (32-bit, non-prefetchable) [size=256] > Capabilities: [80] Power Management version 2 I was referring to the USB adapter in the enclosure, not the one in your computer. It's possible however that there's some weird incompatibility between the two adapters. On the other hand, the fact that your drive fails when plugged into different computers indicates that there really is something wrong with the interface in the enclosure. > > There was a discussion a few months ago from someone who found > > that his USB-IDE adapter would fail every time he tried to transfer > > sectors containing a certain pattern of 3 or 4 bytes right at the sector > > boundary. See these email threads: > > > > http://marc.theaimsgroup.com/?l=linux-usb-devel&m=107962180123336&w=2 > > > > and > > > > http://marc.theaimsgroup.com/?l=linux-usb-devel&m=108045000409630&w=2 > > That's a Genesys issue. Well, this was a Genesys interface, but it wasn't the normal sort of failure we've seen with them. No one else with a Genesys adapter was able to duplicate this particular problem, and IIRC it occurred under Windows as well as Linux. To me that indicates a specific hardware failure. > We all know the Genesys adapters are > fundamentally broken. I have VIA in the host, and Cypress in the > enclosure. There has been progress recently on the Genesys front, thanks to some advice from the Genesys technical support people. So at the moment they are probably about as reliable as the Cypress interfaces. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by BEA Weblogic Workshop FREE Java Enterprise J2EE developer tools! Get your free copy of BEA WebLogic Workshop 8.1 today. http://ads.osdn.com/?ad_id=4721&alloc_id=10040&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
