[issue1231] The problem with USB stick and msdosfs

[Simon 'corecode' Schubert]

Jeremy Chadwick wrote:
> 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.

Yes.  Smaller writes are much worse than larger writes.