Large msdosfs disk will not mount on RELENG_6

Richard Coleman rcoleman at criticalmagic.com
Sun Nov 26 22:26:33 PST 2006


Clayton Milos wrote:
> 
> ----- Original Message ----- From: "Richard Coleman" 
> <rcoleman at criticalmagic.com>
> To: <freebsd-stable at freebsd.org>
> Sent: Monday, November 27, 2006 5:23 AM
> Subject: Large msdosfs disk will not mount on RELENG_6
> 
> 
>> I just bought a large external hard drive for home backups (500g 
>> Western Digital My Book).  When I plug it in to my machine (RELENG_6 
>> from about a week ago), the system sees the device just fine:
>>
>> Nov 26 22:03:21 neptune kernel: umass0: Western Digital External HDD, 
>> rev 2.00/1.06, addr 2
>> Nov 26 22:03:21 neptune kernel: uhid1: Western Digital External HDD, 
>> rev 2.00/1.06, addr 2, iclass 8/6
>> Nov 26 22:03:21 neptune kernel: da0 at umass-sim0 bus 0 target 0 lun 0
>> Nov 26 22:03:21 neptune kernel: da0: <WD 5000YS External 106a> Fixed 
>> Direct Access SCSI-4 device
>> Nov 26 22:03:21 neptune kernel: da0: 40.000MB/s transfers
>> Nov 26 22:03:21 neptune kernel: da0: 476940MB (976773168 512 byte 
>> sectors: 255H 63S/T 60801C)
>>
>>
>> But when I try to mount the drive (mount -t msdos /dev/da0 /mnt), the 
>> system gives the following error:
>>
>> Nov 26 22:06:41 neptune kernel: mountmsdosfs(): disk too big, sorry
>>
>> I was surprised to see a file system limitation on FreeBSD that 
>> Windows does not have.  I will probably reformat the system to ufs2, 
>> but thought I would mention this error message.  I'm sure these drives 
>> will become increasingly common.
>>
>> Richard Coleman
>> rcoleman at criticalmagic.com
> 
> I am very suprised at all that windows would allow you to format a 500G 
> drive into a single 500G FAT32 partition.
> 
> As far as I am aware windows 2000 and xp will only allow you to format 
> up to a 32G dive with FAT32. Any bigger and it will force you to use 
> NTFS. The other strange thing is tht you are trying to mount /dev/da0 
> and not /dev/de0s1.
> 
> How did you format this drive ?
> 
> -Clay

I didn't format it.  This was "out of the box".  To be honest, I forgot to look to see how much of 
the disk that Windows XP could see.  And I needed to use the drive, so unfortunately I've already 
nuked the msdosfs stuff and reformatted it with ufs2.

Looking at the (meager) documentation that came with the drive, it just says that it was 
preformatted as a single FAT32 partition for compatibility.

As to using da0 rather than da0s1, that's how I've always seen to mount a msdosfs partition (and it 
works for my 256M usb key drive).

Richard Coleman
rcoleman at criticalmagic.com


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