Carl Lowenstein wrote:
> On Jan 3, 2008 12:20 AM, Carl Lowenstein <[EMAIL PROTECTED]> wrote:
>> On Jan 2, 2008 11:47 PM, James G. Sack (jim) <[EMAIL PROTECTED]> wrote:
>>> Carl Lowenstein wrote:
>>>> I just got a new USB disk drive and have encountered some interesting
>>>> problems trying to use it.
>>> What model drive is it?
>>> Not a Seagate FreeAgent, is it?
>>>
>>> Justaguess:
>>>  # rmmod usb_storage && modprobe usb_storage
>> Maxtor 500GB SATA (today's Fry's special) in an Acomdata box (another
>> Fry's special).
>> This is the second of these Acomdata boxes I have purchased recently,
>> and the first one is working well.  (although I have not tried it with
>> either of the laptops)
> 
> More experimental evidence.  Working with the Presario (64-bit dual
> Turion, Ubuntu 7.10).
> 
> As I noted before, if I connect the USB hard drive to the computer and
> then boot the OS, the drive is recognized and mounted at
> /media/<volume_label>.  It is /dev/sdb
> 
> If I unmount the drive with the GUI, the mount point
> /media/<volume_label> goes away but /dev/sdb is still there.  I can
> mount and umount it by command line, at my own choice of mount point.
> If I then pull the cable, /dev/sdb goes away.  But I can't just plug
> the cable in again and get it back.
> 
> Today's experiments, with much confusion involved.  Boot the OS.  Then
> connect the USB hard drive.  Get much complaint logged by dmesg.
> Including the interesting one:
> irq7: nobody cares.   Try booting with "irq_poll" option.
> Tried it, nothing better happened.
> 
> Boot computer again, connect the USB hard drive.  Do "lsmod" to see
> modules.  Then connect a USB memory stick.  Presto, voila', _both_
> drives are recognized and mounted.  They are /dev/sdb and /dev/sdc,
> and are mounted at /media/<volume_label> and /media/disk respectively.
>  Something happens when the memory stick is mounted that stimulates
> mounting of the hard drive.
> 
> Presumably if I unmount the memory stick, the hard drive will still be there.
> 
> $ cat /proc/scsi/scsi gives the appropriate drive identification data.
> 
> Side question, generated while looking at lsmod output.  It comes in 3
> columns, headed:
> Module    Size   Used By
> 
> I understand Module and Size.  But the first entry in the Used By
> column is a small integer.  It looks like it might be a count of the
> number of entries in "Used By" and sometimes it is.  But not always.
> Groveling through the man.page and source for lsmod I find that it is
> merely reformatting the contents of /proc/modules.  But that doesn't
> help.

You may be experiencing a udev problem. Try looking in
/etc/udev/rules.d/ and see if there are any files that have been set up
for persistent storage. Sometimes the generated rules are too strict and
will refuse to detect a device because it doesn't match some seemingly
arbitrary criteria.

The whole autodetect thing is governed by udev and hald, and although I
know generally how it's supposed to work I haven't slogged through the
details yet. It has some very annoying behaviors.

Gus


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