western digital mybook (external usb drive, 250gb) takes 15 minutes to be recognized

Brian King free.as.in.speech at gmail.com
Thu Oct 5 13:51:01 UTC 2006


hi roland,

i formatted the disk and created a single bsd slice, but no luck.

it's interesting to hear that the mybook 500gb version works fine, as well
as freebsd releng6 from sep.19.

i'm going to hook mine up someplace else on the network, so i'm not going to
compile a new kernel with the CAMDEBUG option.

thanks again for you suggestions and help!
brian

On 10/1/06, Roland Smith <rsmith at xs4all.nl> wrote:
>
> On Sun, Oct 01, 2006 at 12:32:06AM +0200, Brian King wrote:
>
> > >I've got an external harddrive with a WD disk. It works without
> > >problems;
> <snip>
> > interesting.  perhaps it's something specific to the MyBook.  i'm
> guessing
> > that you don't have a MyBook?
>
> Correct.
>
> > >no other messages related to the drive are displayed on the console
> during
> > >> these 15 minutes.
> > >>
> > >> once the da0 device is recognized, i can mount the partitions (i've
> got
> > >it
> > >> split into two roughly equal-sized primary partitions, one ext2fs and
> > >one
> > >> msdos), e.g.:
> > >> mount -t ext2fs /dev/da0s1/mnt/backup
> > >
> > >Maybe the driver is looking for FreeBSD slices? Do you see any disk
> > >activity
> > >during this 15 minute period?
> >
> >
> > no, i haven't noticed any.  in fact, after about 10 minutes the disk
> spins
> > down because there's been no activity.
>
> Then I guess it's time for some kernel debugging. ;-)
>
> <snip>
> > ... and then the long pause before it attaches to da0 (nothing more is
> > displayed at time of attachment)
> >
> > "camcontrol devlist" gives this right after plugging in the drive:
> > <WD 2500JB External 0107>          at scbus0 target 0 lun 0 (probe0)
> >
> > and after it finally attaches to da0 "camcontrol devlist" gives:
> > <WD 2500JB External 0107>          at scbus0 target 0 lun 0 (pass0,da0)
> >
> > so it seems that the probe phase is what is taking so long.
>
> Could be. But it could also be the creation of the appropriate
> devices. So it might be CAM, devfs or a combination of the two.
>
> > is there any
> > way to specify what action to take when this specific drive is attached,
> > instead of having the system probe it?
>
> Sorry, I don't know.
>
> > i also tried running devd verbosely in the foreground (/sbin/devd -d
> -D).
> > here is the output when the drive is attached:
> > --------
> <snip>
> > --------
> > ... and then the long pause before it attaches to da0 (nothing more is
> > displayed at time of attachment)
>
> That more or less rules out devd, I'd say.
>
> > this MyBook doesn't have any delay when connecting on linux (ubuntu 6.06)
> or
> > on windows xp on this computer.
> >
> > any ideas?  i'm stumped at this point...
>
> Could you test if it makes a difference if there are BSD slices on it?
>
> Otherwisw check the partition table with fdisk to see if the partition
> table is OK.
>
> According to §7.3 of "The design and implementation of the FreeBSD
> operating system" attach operations for da devices are handled in the
> "CAM peripheral layer", one ot the three layers in the CAM subsystem.
>
> It might be usefull to build a kernel with the CAM driver built-in
> complete with the CAMDEBUG option, see cam(4). You can then use
> camcontrol(8) to enable debugging options, e.g. CAM_DEBUG_CDB.
>
> Roland
> --
> R.F.Smith                                   http://www.xs4all.nl/~rsmith/
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>
>


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