Joshua Radke wrote:
> Ok, this one has really gotten me, and google hasn't bailed me out yet, 
> so I was hoping someone on the list could.
> 
> Some relevant system Info are an Athlon XP 1800+, nForce2 chipset 
> motherboard, RT2561(?) wireless card, 40 GB internal (IDE) disk, and 
> 500GB External Western Digital MyBook USB drive, running MythBuntu 
> 7.10.  The kernel is 2.6.22-14-generic #1 SMP Tue Dec 18 08:02:57 UTC 
> 2007 i686 GNU/Linux.
> 
> Note that I (until recently) had the same setup/problems with a Fedora 
> 7/MythTV setup (on the same computer).
> 
> Relevant portion of /var/log/messages:
> Feb 15 12:23:21 venus kernel: [23306.544344] usb 3-6: USB disconnect, 
> address 3
> Feb 15 12:23:25 venus kernel: [23310.022118] lost page write due to I/O 
> error on dm-0
> <repeat above ... a bunch of times>
> Feb 15 12:23:33 venus kernel: [23318.120350] usb 3-6: new high speed USB 
> device using ehci_hcd and address 4
> Feb 15 12:23:33 venus kernel: [23318.254619] usb 3-6: configuration #1 
> chosen from 1 choice
> Feb 15 12:23:33 venus kernel: [23318.255811] scsi1 : SCSI emulation for 
> USB Mass Storage devices
> Feb 15 12:23:36 venus kernel: [23321.068823] printk: 475 messages 
> suppressed.
> Feb 15 12:23:36 venus kernel: [23321.068831] lost page write due to I/O 
> error on dm-0
> Feb 15 12:23:36 venus kernel: [23321.068842] lost page write due to I/O 
> error on dm-0
> Feb 15 12:23:38 venus kernel: [23323.251000] scsi 1:0:0:0: 
> Direct-Access     WD       5000AAK External 1.06 PQ: 0 ANSI: 0
> Feb 15 12:23:38 venus kernel: [23323.253219] sd 1:0:0:0: [sdb] 976773168 
> 512-byte hardware sectors (500108 MB)
> Feb 15 12:23:38 venus kernel: [23323.253842] sd 1:0:0:0: [sdb] Write 
> Protect is off
> Feb 15 12:23:38 venus kernel: [23323.256121] sd 1:0:0:0: [sdb] 976773168 
> 512-byte hardware sectors (500108 MB)
> Feb 15 12:23:38 venus kernel: [23323.256836] sd 1:0:0:0: [sdb] Write 
> Protect is off
> Feb 15 12:23:38 venus kernel: [23323.256849]  sdb: sdb1
> Feb 15 12:23:38 venus kernel: [23323.258946] sd 1:0:0:0: [sdb] Attached 
> SCSI disk
> Feb 15 12:23:38 venus kernel: [23323.259003] sd 1:0:0:0: Attached scsi 
> generic sg0 type 0
> 
> ... and a few minutes later the wife (at home) patiently reboots the 
> computer, and wonders why I got her hooked on this silly machine.
> 
> This issue is that the USB bus resets, and when the external disk is on 
> an LVM2 volume, the dm entry is not removed.  When the USB disk comes 
> back online, it gets another /dev/sd? entry, and cannot be accessed 
> until we've done some cleanup, as in (as root, of course):
> 
> /etc/init.d/myth-backend stop
> umount /storage
> dmsetup delete <LVName>
> vgscan
> lvscan
> vgchange -ay
> mount /storage
> /etc/init.d/myth-backend start
> 
> Phew!  Now ... I've considered adding this as a script to a 
> /etc/udev/rules.d/10-local.rules file (to match the serial number of the 
> disk, for example), but this is not a solution, only a way to let my 
> wife only notice the issues minimally (though it would have the side 
> effect of chopping up recordings into pieces with the backend restarts)..
> 
> Note that the previous Fedora setup had the storage partition on a 
> primary partition (not LVM), so the USB drive would (upon reconnect) end 
> up with the same letter, and reading/writing from myth-backend would 
> simply resume after a pause.
> 
> Some other things I've tried:
> boot the kernel with
> acpi=off (no noticable difference)
> Add the following to /etc/udev/rules.d/10-local.rules
> SYSFS{serial}=="574341533830343230313137",RUN+="/bin/sh -c '/bin/echo 64 
>  > /sys/block/%k/device/max_sectors'"
> 
> Some of these were suggested in 
> (https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/61235)
> 
> Picking through
> sdparm -al /dev/sda
> shows '0' for IDLE and STANDBY entries.
> 
> Note that the problem appeared to be much more pronounced (resetting 
> every 10's of minutes instead of one to three times per day) when I had 
> the PCI bus underclocked in the BIOS ... I have since gotten a better 
> cooling solution, and no longer need to do that for stability.
> 
> Finally, downgrading the usb to 1.1 (modprobe -r ehci_hcd) appeared to 
> solve the USB resets, but there was not quite enough bandwidth left to 
> both play and record to the disk.  (Playback would skip every couple of 
> seconds ... the kids didn't care, but it'd drive my wife and I nuts!).
> 
> Any hints?
> 
> Thanks,
> 
> Josh
> 
> 
> _______________________________________________
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Have you checked dmesg to see if you are getting any acpi errors? Have
you tried a plugin USB board to see if that helps?

You could also try rebuilding the kernel with usb debug enable and see
if that pin points the problem.

Joseph