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-by\x2duuid-f5086632\x2dd819\x2d486a\x2d8c42\x2d920fe78b9644.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