KAWAMATA Yoshihiro wrote:
I have measured write/remove time with the USB flash drive;
sd0 at scsibus2 targ 1 lun 0: <TOSHIBA, TransMemory, PMAP> SCSI0 0/direct
removable
sd0: 961MB, 512 bytes/sec, 1968128 sec total
First, I copied file tree (about 100MB) from mfs to such USB flash drive, then
umount.
Next, mount it again, then remove all files and directories.
(test script at the end of this mail)
You need to include the time to "sync" (or umount) after writing and
deleting the files, otherwise you arent benchmarking the USB speed but
rather how fast your caches are, since the time for rm -rf * will be
spent at the umount (which you didnt include in the timing) instead,
when flushing the pending writes/deletes.
Just like windows will write REALLY fast to your USB-stick, then you
have to wait for the "eject removable device" instead if you try to take
it out quickly after a large copy.
