All,
I have a USB disk (a 320GB Western Digital My Passport) which is
exhibiting the following problem.
When first hooked up and mounted, it works fine. I've successfully
transferred 100's of GB onto the disk.
However, if left idle for some hours, it fails when accessed, with a
spontaneous USB disconnect and reconnect of the device (log excerpts below).
Some hours later, it still gives immediate I/O errors when accessed (e.g.
with ls), but unmounting and re-mounting the drive makes it work again.
(It might have also needed a physical unplug and re-plug once, but I don't
recall for sure.)
It is a 2.5" disk with no external power supply, just power from USB. This
happens in multiple port group and multiple cables. I have another USB
disk, this one a 3.5" IDE drive which I installed in a USB enclosure
myself, that does have external power, that works with no problems.
Now, the unmount/remount cycle suggests that I could perhaps work around
the problem with automount. But, if the disk is just plain defective, I
don't want to paper over the problem.
I wonder if the computer can't provide enough power to run the device (it
exceeds the 500mA/port limit, though that was NOT clear in the newegg
description). However, if that's true, why does it only fail after a long
idle?
Thoughts?
Many thanks in advance,
Reid
Log excerpt 1 (failure during stat()):
Jan 29 02:27:07 reidster kernel: [7125216.194039] usb 4-4: USB disconnect, address 12
Jan 29 02:27:07 reidster kernel: [7125216.198039] sd 23:0:0:0: [sdc] Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK,SUGGEST_OK