umass0: Kingston DataTraveler 2.0, rev 2.00/1.00, addr 2
da0 at umass-sim0 bus 0 target 0 lun 0
da0:
da0: 40.000MB/s transfers
da0: 1968MB (4030464 512 byte sectors: 255H 63S/T 250C)
第1次拔出优盘后，屏幕输出如下信息：
umass0: at uhub1 port 1 (addr 2) disconnected
(da0:umass-sim0:0:0:0): lost device
(da0:umass-sim0:0:0:0): removing device entry
umass0: detached
第2次插入优盘后，屏幕输出如下信息：
umass0: Kingston DataTraveler 2.0, rev 2.00/1.00, addr 2
da1 at umass-sim0 bus 0 target 0 lun 0
da1:
da1: 40.000MB/s transfers
da1: 1968MB (4030464 512 byte sectors: 255H 63S/T 250C)
挂装优盘：
在/mnt目录下新建文件夹/usb,mkdir /mnt/usb
mount -tmsdos /dev/da0s1 /mnt/usb 或 mount -tmsdos /dev/da1s1 /mnt/usb
完毕。