Message-ID: <3A084720.8000800@speakeasy.org>
Date: Tue, 07 Nov 2000 10:17:04 -0800
From: Miles Lane <miles@speakeasy.org>
User-Agent: Mozilla/5.0 (X11; U; Linux 2.4.0-test10 i686; en-US; m18) Gecko/20001102
MIME-Version: 1.0
To: Andries Brouwer <aeb@veritas.com>
CC: Matthew Dharm <mdharm@one-eyed-alien.net>, linux-kernel@vger.kernel.org
Subject: Re: 2.4.0-test10 -- Problem reading VFAT formatted ORB drive.
In-Reply-To: <3A07C0BF.4060607@speakeasy.org> <20001107054550.A15541@veritas.com>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org

Andries Brouwer wrote:

> On Tue, Nov 07, 2000 at 12:43:43AM -0800, Miles Lane wrote:
> 
> 
>> I have an ORB drive I am accessing using the usb-storage driver.
>> I formatted the drive media last night using Windoze 98.  The media
>> was formatted as though it had one large partition, which is weird
>> because I had previously partitioned the drive under Linux 2.4.0-test10
>> with several partitions.  The Windoze format utility did not notice
>> those partitions and simply (I thought) wrote one large partition and
>> formatted it as VFAT.  I have successfully written and read data on
>> the media using two separate Windoze 98 machines.  When I mounted
>> the drive under 2.4.0-test10 and then looked at the media with
>> fdisk, here's what I see:
>> 
>> #> fdisk /dev/sda
>> 
>> Disk /dev/sda: 68 heads, 62 sectors, 1021 cylinders
>> Units = cylinders of 4216 * 512 bytes
>> 
>>     Device Boot    Start       End    Blocks   Id  System
>> /dev/sda1   ?    455397    584533 272218546+  20  Unknown
>> Partition 1 has different physical/logical beginnings (non-Linux?):
>>       phys=(356, 97, 46) logical=(455396, 22, 59)
> 
> ...
> 
>> What's going on here?  It seems to me that this is a bug in the
>> Linux test10 filesystem support, since Windoze can read and write
>> to this drive currently.  Our implementation should be compatible.
> 
> 
> Well, clearly (i) you can read it, and (ii) you don't like the contents.
> With these removable disks there are often two possibilities:
> either format the thing as a large floppy (without partition table)
> or format it as a disk.
> Maybe you did the former. (In that case, "mount /dev/sda" might work.)
> 
> If you can't find out what happened, I wouldnt mind seeing
> the first 64 sectors or so.
> 
> (By the way, the geometry is interesting: 1021/68/62.
> My web page says:
>   "The size is 2.2 GB. Castlewood recommends a C/H/S = 4273/16/63 geometry,
>    which multiplies out to 4307184 sectors, that is, 2205278208 bytes.
>    The default geometry with which the IDE version of the drive is shipped
>    gives only 528 MB."
> Now 68*62*1021*512=2203922432, almost full capacity. I wonder who
> invented it.)
> 
> Andries
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> Please read the FAQ at http://www.tux.org/lkml/

Thanks to you and Matt (who also sent this idea to me).
You are correct, the drive got formatted with no partition
table.  I had never heard, before, that a disk could be
formatted without a partition.  I also am surprised to
discover that the ORB drive got formatted this way.

Thankyou both for the education!

	Miles

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/