Re: 2.4.0-test10 -- Problem reading VFAT formatted ORB drive.

From: Miles Lane (miles@speakeasy.org)
Date: Tue Nov 07 2000 - 13:17:04 EST


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
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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

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