More USB woes

[Eric Battersby]

On Sun, 21 Mar 2010, Thomas Milne wrote:

> Today I shut down my computer to get the dust out, and when I booted
> back up, my big external drive would not mount (panic), so again I
> looked at /var/log/messages to see what I could see. Eventually it did
> mount (whew!), but this is what I saw in messages:
>
> Mar 21 13:50:24 node1 kernel: [  575.712023] usb 1-4: reset high speed
> USB device using ehci_hcd and address 8
> Mar 21 13:50:25 node1 kernel: [  575.964035] usb 1-4: reset high speed
...
> Mar 21 13:50:27 node1 kernel: [  578.617710] sd 2:0:0:0: [sda] Result:
> hostbyte=DID_ERROR driverbyte=DRIVER_OK
> Mar 21 13:50:27 node1 kernel: [  578.736021] usb 1-4: reset high speed
...
> Is there something wrong with my computer? I don't get this with my
> iPod when I plug it in, and now the USB key that was not working
> previously this week (see other USB thread) now is working, no errors
> in messages.

I used to get these messages often with USB drives
larger than 500GB (which may explain the iPod), while
the drive was mounted and during writing!
I have an older computer a Dell Lattitude C640 (circa 2002).
What is the vintage of your computer?
How often do you turn your USB drive off?

My advice:
- do not use USB
OR
- disconnect USB cable
- turn off automount
- turn drive on and let it warm up for 45m
- tail -f /var/log/messages in separate window
- while drive not connected
  - connect drive
  - if OK (according to 'messages'), then mount
  - else, disconnect USB, wait 15s

You also might want to consider altering
'/sys/block/sd?/device/max_sectors' to a smaller block size
just before mounting.
After connecting, I set mine to '64'.
I don't know for sure if that helps, but it seems to.


--
Eric B.
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