Large msdosfs disk will not mount on RELENG_6

[secmgr]

On Sun, 2006-11-26 at 19:23, Richard Coleman wrote:
> 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.

Would you share how you initialized this drive, and what parameters you
used?  FAT32 has a 2 TB limit for the filesystem and 2 GB for a file. 
The error you saw is thrown when the # of sectors exceeds an unsigned 32
bit integer.

BTW, the limit is based on the DOS spec, not FreeBSD.

jim