AAARRRGGGHHH!!! Re: USB CD Burners? - Problem

[Brian Chabot]

Ok.

The machine runs:
$ uname -a
Linux alfred.datasquire.net 2.6.11-6mdk #1 Tue Mar 22 16:04:32 CET 2005
i686 AMD Athlon(tm) XP 2200+ unknown GNU/Linux

Here's the deal.  Now I attach the drive ,and within SECONDS I get:
Apr  7 00:21:36 alfred kernel: usb 4-5: USB disconnect, address 4

WTF?!?

The CD burner continues with the last comman it got as if nothing
happened and my system has processes I can't kill:

8253 ?        00:00:00 scsi_eh_0
8254 ?        00:00:00 usb-storage
8312 ?        00:00:04 k3b
[root at alfred ~]# kill -s 9 8253
[root at alfred ~]# kill -s 9 8253
[root at alfred ~]# kill -s 9 8254
[root at alfred ~]# kill -s 9 8254
[root at alfred ~]# kill -s 9 8254
[root at alfred ~]# kill -s 9 8312
[root at alfred ~]# kill -s 9 8312
[root at alfred ~]# kill -s 9 8312
[root at alfred ~]# kill -s 9 8312

dmesg tells me:
usb 4-5: new high speed USB device using ehci_hcd and address 4
SCSI subsystem initialized
Initializing USB Mass Storage driver...
scsi0 : SCSI emulation for USB Mass Storage devices
usbcore: registered new driver usb-storage
USB Mass Storage support registered.
usb-storage: device found at 4
usb-storage: waiting for device to settle before scanning
  Vendor: Memorex   Model: 52MAXX 3252AJ1    Rev: 4WS2
  Type:   CD-ROM                             ANSI SCSI revision: 00
usb-storage: device scan complete
sr0: scsi3-mmc drive: 255x/52x writer cd/rw xa/form2 cdda tray
Attached scsi CD-ROM sr0 at scsi0, channel 0, id 0, lun 0
Attached scsi generic sg0 at scsi0, channel 0, id 0, lun 0,  type 5
usb 4-5: USB disconnect, address 4

A reboot (either a reboot command or an init 6 or 0) now hangs.

WTF?




Ben Scott wrote:
> On Apr 4, 2005 2:46 AM, Brian Chabot <brian at datasquire.net> wrote:
> 
>>Now I burn a CD.  Any CD.  I like to make sure it burns well, so I have
>>k3b check the disk and it gets about 70% of the way through and hangs
>>for a few minutes.  Then it errors out that the verification could not
>>complete.
> 
> [...]
> 
>>Apr  4 02:30:31 alfred kernel: sr0: Current: sense key: Medium Error
>>Apr  4 02:30:31 alfred kernel:     Additional sense: Unrecovered read error
> 
> 
>  Well, "Medium error" indicates a problem with the medium, i.e., a
> problem with the actual disc.  You'll notice that it comes from the
> "sr" (SCSI CD-ROM) device driver.  That is not used for writing CDs --
> only for reading them.  The "sg" (SCSI generic) driver is used for
> writing to discs.  So this is not a problem with the write process
> itself.
> 
>  Something I've had trouble with in the past are the various "auto
> mount on media load" gadgets.  That is, daemons that poll devices to
> see if media has been inserted, and automatically mount it if so.  The
> intent is to make it so that users don't have to manually mount media;
> they just stick the disc in and it magically appears on their GUI
> desktop.  The problem occurs when these gadgets poll a drive which is
> half-way through writing a new CD.  That obviously isn't going to
> work, and causes the drive itself to get all confused, which causes
> the whole thing to puke.
> 
>  I solve this problem by killing off and disabling all those
> auto-magic mount gadgets.  I don't like them anyway, cause I'm an
> old-school control freak and like to mount my media manually, the way
> man was intended to.  There's probably a more sophisticated solution,
> but this worked for me.
> 
>  YMMV.  HTH.
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