Flash Disk

Teilhard Knight teilhk at crosswinds.net
Fri Jan 6 21:17:54 PST 2006

> Hi,
> Please don't remote the list from the recipients of the message, unless
> the reply contains confidential material that you don't wish to disclose
> to all the subscribers of the list.  By keeping the list, you ensure
> that other subscribers may reply too in case I'm wrong about something,
> and you make it possible for future readers who find the thread in the
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I am aware of the importance that the discussions take place in the list.
It, I confess, happens with my newsreader that if I just hit: "reply", the
address entered in the reply is the sender's address, and I have sent many
messages that way for not correcting it. But invariably I have realized the
mistake and copy and paste my reply to the list again. So, in that case the
person I am replying to receives two messages, one in the list and one
private. I have no account of having replied only to the recipient.

> On 2006-01-06 00:07, Teilhard Knight <teilhk at crosswinds.net> wrote:
>>> When I plug my USB JetFlash disk, the following appears in
>>> /var/log/messages (and the system console, but I mostly use X11
>>> these days):
>>>    umass0: USB Flash Disk, rev 2.00/2.00, addr 2
>>>    da0 at umass-sim0 bus 0 target 0 lun 0
>>>    da0:  Removable Direct Access SCSI-2 device
>>>    da0: 1.000MB/s transfers
>>>    da0: 250MB (512000 512 byte sectors: 64H 32S/T 250C)
>> I get something similar too. The Device Node is created all right.
> Cool!


>>> When you plug the USB flash disk in, /dev/da0 (or another daX
>>> device) is automatically created.  If the flash disk already has
>>> partitions (they usually come with a single FAT partition),
>>> you'll also see da0s1 or something similar:
>>>    # ls -l /dev/da*
>>>    crw-r-----  1 root  operator  -   4,  44 Oct 16 17:38 /dev/da0
>> Yes, I also get something similar to this.
> That's nice.  It means that the kernel has recognized the flash disk as
> a "block device" and the CAM layer of the kernel has created a 'direct
> access' disk device for it -- much like it does for SCSI disks.


>>> If you see only da0, it's possible that the 'raw disk' is
>>> formatted using FAT, without a real BIOS-style partition, which
>>> means that you should be able to 'mount' it with something like:
>>>    # /sbin/mount_msdosfs /dev/da0 /mnt
>> I do not only see da0 above and this command results in: "mount_msdosfs:
>> /dev/da0: Invalid argument"
> The flash disk is not formatted, so you'll have to create a filesystem
> on it.  I did this for mine, using fdisk(8) and bsdlabel(8), as
> described in the following post of my old weblog:
> http://keramida.serverhive.com/weblog/archives/2004-10-16/using-a-usb-20-flash-mini-disk-on-freebsd

The disk was formatted all right. The problem I had is that I was trying to
mount /dev/da0, instead of /dev/da0s1.

> Enabling USB 2.X will also increase the access speed of the flash disk a
> lot, so you may want to read this too:
> http://keramida.serverhive.com/weblog/archives/2005-06-23/usb-2x-support-in-freebsd

I only have USB 2.0 in my computer. Actually I would like to have at least
one port 1.1 for some old devices.

>> You told me how to mount my flash disk in case the command "ls -l
>> /dev/da0" results incomplete or I have the disk raw formatted. But
>> what should I do if I get all similar to what you get? In other words,
>> how do you mount your flash disk?
> If you successfully mount the disk once, using the mount(8) and the
> related utilities (mount_msdosfs, etc), then you can add a line in your
> ``/etc/fstab'' file to make things easier the next time.  My USB disk
> doesn't have slices these days (just a UFS filesystem on it) so the
> relevant line from fstab is:
>    /dev/da1a /mnt/jflash ufs rw,noauto,noexec,nosuid 0 0

Yes, I have written a line similar to this in /etc/fstab, and I now just
hit: "mount /mnt/Ant". Ant is the label of my flash disk.

I very much appreciate your feedback.


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