As I open /etc/fstab, I found following,
#rootfs / auto defaults 1 1
proc /proc proc defaults 0 0
devpts /dev/pts devpts mode=0620,gid=5 0 0
#usbfs /proc/bus/usb usbfs defaults 0 0
tmpfs /var/volatile tmpfs defaults,size=16M 0 0
tmpfs /dev/shm tmpfs mode=0777 0 0
tmpfs /media/ram tmpfs defaults,size=16M 0 0
Did you know why below are mark??
#rootfs / auto defaults 1 1
#usbfs /proc/bus/usb usbfs defaults 0 0
