问题描述：
系统版本：Ubuntu 16.04.5 LTS
内核：4.4.0-131-generic
执行 mount /dev/sdn /data/disk8 无错误返回，/var/log/syslog提示信息如下：
Nov 19 11:12:08 bjxg-dp-49-30 kernel: [18304371.864422] EXT4-fs (sdn1): mounted filesystem with ordered data mode. Opts: (null) Nov 19 11:12:08 bjxg-dp-49-30 systemd[1]: data-disk8.mount: Unit is bound to inactive unit dev-disk-byx2duuid-f5086632x2dd819x2d486ax2d8c42x2d920fe78b9644.device. Stopping, too. Nov 19 11:12:08 bjxg-dp-49-30 systemd[1]: Unmounting /data/disk8... Nov 19 11:12:08 bjxg-dp-49-30 systemd[1]: Unmounted /data/disk8. Nov 19 11:12:08 bjxg-dp-49-30 systemd[1]: data-disk8.mount: Unit entered failed state.
解决方式：
systemctl daemon-reload mount /dev/sdn /data/disk8