Running FreeBSD 6.0 here. I have a USB-attached floppy/CF/SD combo reader. On powerup it is detected and I get /dev/da0 as the CF slot: da0 at umass-sim0 bus 0 target 0 lun 0 da0: <OEI-USB CompactFlash 2.0> Removable Direct Access SCSI-0 device da0: 1.000MB/s transfers da0: Attempt to query device size failed: NOT READY, Medium not present da1 at umass-sim0 bus 0 target 0 lun 1 da1: <OEI-USB SM/MS/SD 2.0> Removable Direct Access SCSI-0 device da1: 1.000MB/s transfers da1: Attempt to query device size failed: NOT READY, Medium not present However, when I insert a CF card with normal partioning I need /dev/da0s1, and this is not present in the /dev filesystem because the partition table has not been read. # mount -t msdos /dev/da0s1 /mnt/cf mount_msdosfs: /dev/da0s1: No such file or directory Just reading the first block is not sufficient: # dd if=/dev/da0 of=/dev/null count=1 1+0 records in 1+0 records out 512 bytes transferred in 0.040984 secs (12493 bytes/sec) # mount -t msdos /dev/da0s1 /mnt/cf mount_msdosfs: /dev/da0s1: No such file or directory The only way I can see to *force* the superblock to be read is to attempt to mount the whole device as if it were unpartitioned. This is sufficient to cause the /dev/da0s1 entry to appear in the /dev filesystem. # mount /dev/da0 /mnt/cf mount: /dev/da0 on /mnt/cf: incorrect super block # mount -t msdos /dev/da0s1 /mnt/cf # At this point, everything works as expected. My question is: is there an easier or more direct way to cause the partition table of the CF card to be read and the /dev filesystem to update? Thanks, Brian Candler.
On Wed, Nov 16, 2005 at 10:12:00AM +0000, Brian Candler wrote:> Running FreeBSD 6.0 here. > > I have a USB-attached floppy/CF/SD combo reader. On powerup it is detected > and I get /dev/da0 as the CF slot: > > da0 at umass-sim0 bus 0 target 0 lun 0 > da0: <OEI-USB CompactFlash 2.0> Removable Direct Access SCSI-0 device > da0: 1.000MB/s transfers > da0: Attempt to query device size failed: NOT READY, Medium not present > da1 at umass-sim0 bus 0 target 0 lun 1 > da1: <OEI-USB SM/MS/SD 2.0> Removable Direct Access SCSI-0 device > da1: 1.000MB/s transfers > da1: Attempt to query device size failed: NOT READY, Medium not present > > However, when I insert a CF card with normal partioning I need /dev/da0s1, > and this is not present in the /dev filesystem because the partition table > has not been read.<snip>> The only way I can see to *force* the superblock to be read is to attempt to > mount the whole device as if it were unpartitioned. This is sufficient to > cause the /dev/da0s1 entry to appear in the /dev filesystem.<snip>> At this point, everything works as expected. > > My question is: is there an easier or more direct way to cause the partition > table of the CF card to be read and the /dev filesystem to update?Try 'camcontrol rescan all' (as root). Roland -- R.F.Smith (http://www.xs4all.nl/~rsmith/) Please send e-mail as plain text. public key: http://www.xs4all.nl/~rsmith/pubkey.txt -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 187 bytes Desc: not available Url : http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20051116/6414f036/attachment.bin
Brian Candler <B.Candler@pobox.com> wrote:
> However, when I insert a CF card with normal partioning I need /dev/da0s1,
> and this is not present in the /dev filesystem because the partition table
> has not been read.
>
> # mount -t msdos /dev/da0s1 /mnt/cf
> mount_msdosfs: /dev/da0s1: No such file or directory
>
> Just reading the first block is not sufficient:
>
> # dd if=/dev/da0 of=/dev/null count=1
> 1+0 records in
> 1+0 records out
> 512 bytes transferred in 0.040984 secs (12493 bytes/sec)
> # mount -t msdos /dev/da0s1 /mnt/cf
> mount_msdosfs: /dev/da0s1: No such file or directory
I think devfs is updated when a descriptor on the device
which was opended for writing is closed. But you don't
actually have to write anything. That means, the following
command should do it:
# dd if=/dev/null of=/dev/da0 count=0
Best regards
Oliver
--
Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing
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