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.
