方法1
1.ls /sys/class/scsi_host
   host0 host1 host2                #有几个host就执行几步echo
2.echo "- - -" > /sys/class/scsi_host/host0/scan
3.echo "- - -" > /sys/class/scsi_host/host1/scan
4.echo "- - -" > /sys/class/scsi_host/host2/scan
fdisk -l

方法2
1.cat /proc/scsi/scsi
2.echo "scsi add-single-device 0 0 X 0" > /proc/scsi/scsi 　　　# X是上一步结果id加1