Date: Sun, 26 Feb 2012 10:54:56 +0700 From: Erich Dollansky <erichfreebsdlist@ovitrap.com> To: freebsd-stable@freebsd.org Cc: Scott Bennett <bennett@cs.niu.edu> Subject: Re: random problem with 8.3 from yesterday Message-ID: <201202261054.56403.erichfreebsdlist@ovitrap.com> In-Reply-To: <201202251027.q1PARURH021975@mp.cs.niu.edu> References: <201202251027.q1PARURH021975@mp.cs.niu.edu>
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Hi,
On Saturday 25 February 2012 17:27:30 Scott Bennett wrote:
> On Wed, 22 Feb 2012 13:34:36 +0700 Erich Dollansky
> <erich@alogreentechnologies.com> wrote:
>
> >I got a new thumb drive which was FAT formatted. I use this script to change this:
> >
> >!/bin/tcsh
> >#
> ># 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.
it works since years with all other and even with hard disks. Only the system disk has to be done 'properly'.
>
> >
> >I then call manually
> >
> >tunefs -L NewDeviceName /dev/da0a
>
> Just out of curiosity, I'd like to know why you run tunefs manually,
Historical reasons. It is an old script and I never updated it.
> rather than using "-L NewDeviceName" on the newfs command, given that your
> script is clearing the physical device and then creating an empty file
> system.
> >
> >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.,
I mean the device connected to /dev/da0a just to make clear that I did not use /dev/da0.
>
> 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.,
It is a chicken egg problem. As long as fstab is not updated with the name of the new device, it does not work the other way.
>
> 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 the editing later. It is just a matter of work sequence.
> >
> >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?
Do not forget, that this step does not happen always.
> >
> >uname says:
> >
> >FreeBSD AMD620.ovitrap.com 8.3-PRERELEASE FreeBSD 8.3-PRERELEASE #28: Tue Feb 21 17:15:07 WIT 2012 erich@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
>
> http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/geom-glabel.html#AEN27470
>
It does not explain to me why the device could not be mounted.
I did not have this problem anymore since then. It might be the case that the problem only appears when the drive has a fresh file system or a new label.
I will check this later.
Erich
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