random problem with 8.3 from yesterday

Scott Bennett bennett at cs.niu.edu
Sat Feb 25 11:28:22 UTC 2012

     On Wed, 22 Feb 2012 13:34:36 +0700 Erich Dollansky
<erich at alogreentechnologies.com> wrote:

>I got a new thumb drive which was FAT formatted. I use this script to change this:
># This script format a thumb drive connected to USB as da0.
>printf "You have to run this script as 'root' to succeed.\n"
>printf "Warning this script will delete all your data from /dev/da0. Continue? > "
>set Eingabe = $<
>if ("$Eingabe" == "y") then
>   printf "\nDeleting the device "
>   dd if=/dev/zero of=/dev/da0 bs=1k count=1
>   printf "\nWriting the BSD label "
>   bsdlabel -Bw da0 auto

     Hmmm...so no MBR and no GPT either?  Just the bare device?  I guess
I haven't tried that, so I don't know what that would do.

>   printf "\nEditing the BSD label "
>   bsdlabel -e da0
>   newfs /dev/da0a
>   printf "\nThe device /dev/da0 was formated to be used with FreeBSD.\n"
>   printf "\nScript aborted!\n"
>I then call manually
>tunefs -L NewDeviceName /dev/da0a

     Just out of curiosity, I'd like to know why you run tunefs manually,
rather than using "-L NewDeviceName" on the newfs command, given that your
script is clearing the physical device and then creating an empty file
>Either this call or the mount command does not work randomly.
>When I then try to mount the device on /dev/da0a it does not work always.

     What do you mean when you write "mount the device on /dev/da0a"?
Normally one mounts a filesystem onto a "device", e.g.,

	mount /dev/ad0s1d /var

or some similar thing.  Also, why do you refer to /dev/da0a at all if you
labeled the file system?  The whole point of labeling the file system is
supposed to be so that you can mount it independently of the physical
device name, e.g.,

	mount /dev/ufs/NewDeviceName /thumbfs

which allows you to have an entry in /etc/fstab for mounting the file
system that doesn't need to be edited every time you reboot the system or
move devices around.
>I do not know what this causes, I am only randomly able to reproduce it.
>It might be affected by removing the device or keeping it plugged in.

     Well, yes, that's what you label partitions/devices to avoid having
to deal with manually, right?
>uname says:
>FreeBSD AMD620.ovitrap.com 8.3-PRERELEASE FreeBSD 8.3-PRERELEASE #28: Tue Feb 21 17:15:07 WIT 2012     erich at AMD620.ovitrap.com:/usr/obj/usr/src/sys/AsusAMD620  amd64
>dmesg says:
>ugen1.2: <vendor 0x1005> at usbus1
>umass0: <vendor 0x1005 USB FLASH DRIVE, class 0/0, rev 2.00/1.00, addr 2> on usbus1
>umass0:  SCSI over Bulk-Only; quirks = 0x4001
>umass0:2:0:-1: Attached to scbus2
>da0 at umass-sim0 bus 0 scbus2 target 0 lun 0
>da0: < USB FLASH DRIVE PMAP> Removable Direct Access SCSI-0 device 
>da0: 40.000MB/s transfers
>da0: 15272MB (31277056 512 byte sectors: 255H 63S/T 1946C)
>It is not an urgent problem.
     It most likely is not a problem at all.  See


                                  With best regards,

                                  Scott Bennett, Comm. ASMELG, CFIAG
* Internet:       bennett at cs.niu.edu                              *
* "A well regulated and disciplined militia, is at all times a good  *
* objection to the introduction of that bane of all free governments *
* -- a standing army."                                               *
*    -- Gov. John Hancock, New York Journal, 28 January 1790         *

More information about the freebsd-stable mailing list