[issue1231] The problem with USB stick and msdosfs

[Jeremy Chadwick]

On Fri, Jan 16, 2009 at 08:56:49PM +0000, Hasso Tepper (via DragonFly issue tracker) wrote:
> da0: <pqi IntelligentStick 0.00> Removable Direct Access SCSI-2 device
> da0: 40.000MB/s transfers
> da0: 963MB (1974271 512 byte sectors: 64H 32S/T 963C)
> 
> $ sudo dd if=/dev/zero of=/mnt/file bs=512k count=100
> 100+0 records in
> 100+0 records out
> 52428800 bytes transferred in 1.744845 secs (30047824 bytes/sec)
> $ time sudo umount /mnt
> real    4m7.152s 	<- ?!?!?! 
> user    0m0.008s
> sys     0m0.047s
> $
> 
> It doesn't happen with any other OS (tried Debian, MacOSX and Windows XP) 
> and there is no problem in DragonFly with the very same formatted to UFS 
> either.

Does the behaviour change if you use standard 512-byte blocks?  People
seem to think that USB pen/flash drives behave exactly like hard disks
when it comes to their methodology of storage and block handling -- they
don't.

-- 
| Jeremy Chadwick                                jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |