systemd-fstab-generator

我在排查 Systemd挂载文件系统(自动) 神秘的自动挂载文件系统问题时，找到了根源是 systemd-fstab-generator : 能够自动根据 /etc/fstab 生成 Systemd挂载文件系统(自动) 配置文件 XXXX.mount ，存放到 /run/systemd/generator/ 目录下。

例如， ls -lh /run/systemd/generator/ 可能会看到如下一些类似配置:

/run/systemd/generator/ 目录下存储了 systemd-fstab-generator 自动生成的 Systemd挂载文件系统(自动) 配置

total 112K
-rw-r--r-- 1 root root 362 Jul  6 11:49 boot.mount
-rw-r--r-- 1 root root 351 Jul  6 11:49 data-brick0.mount
-rw-r--r-- 1 root root 355 Jul  6 11:49 data-brick10.mount
-rw-r--r-- 1 root root 355 Jul  6 11:49 data-brick11.mount
-rw-r--r-- 1 root root 351 Jul  6 11:49 data-brick1.mount
-rw-r--r-- 1 root root 351 Jul  6 11:49 data-brick2.mount
-rw-r--r-- 1 root root 351 Jul  6 11:49 data-brick3.mount
-rw-r--r-- 1 root root 351 Jul  6 11:49 data-brick4.mount
-rw-r--r-- 1 root root 351 Jul  6 11:49 data-brick5.mount
-rw-r--r-- 1 root root 351 Jul  6 11:49 data-brick6.mount
-rw-r--r-- 1 root root 351 Jul  6 11:49 data-brick7.mount
-rw-r--r-- 1 root root 351 Jul  6 11:49 data-brick8.mount
-rw-r--r-- 1 root root 351 Jul  6 11:49 data-brick9.mount
-rw-r--r-- 1 root root 178 Jul  6 11:49 dev-disk-by\x2dlabel-SWAP.swap
-rw-r--r-- 1 root root 260 Jul  6 11:49 disk10.mount
-rw-r--r-- 1 root root 260 Jul  6 11:49 disk11.mount
-rw-r--r-- 1 root root 260 Jul  6 11:49 disk12.mount
-rw-r--r-- 1 root root 258 Jul  6 11:49 disk2.mount
-rw-r--r-- 1 root root 258 Jul  6 11:49 disk3.mount
-rw-r--r-- 1 root root 258 Jul  6 11:49 disk4.mount
-rw-r--r-- 1 root root 258 Jul  6 11:49 disk5.mount
-rw-r--r-- 1 root root 258 Jul  6 11:49 disk6.mount
-rw-r--r-- 1 root root 258 Jul  6 11:49 disk7.mount
-rw-r--r-- 1 root root 258 Jul  6 11:49 disk8.mount
-rw-r--r-- 1 root root 258 Jul  6 11:49 disk9.mount
drwxr-xr-x 2 root root  60 Jul  6 11:49 getty.target.wants
-rw-r--r-- 1 root root 228 Jul  6 11:49 home.mount
-rw-r--r-- 1 root root 260 Jul  6 11:49 home-t4.mount
drwxr-xr-x 2 root root 580 Jul  6 11:49 local-fs.target.requires
drwxr-xr-x 2 root root  60 Jul  6 11:49 local-fs.target.wants
-rw-r--r-- 1 root root 220 Jul  6 11:49 -.mount
drwxr-xr-x 2 root root  60 Jul  6 11:49 multi-user.target.wants
drwxr-xr-x 2 root root  60 Jul  6 11:49 swap.target.requires

这些由 systemd-fstab-generator 生成的 units 没有对应的 unit-files ，所以需要使用以下命令查看:

使用 systemctl 检查 mount 类型 units

systemctl list-units --type mount

输出案例如下:

mount 类型 units 可以看到要删除但是没有删除成功的挂载配置

  UNIT                          LOAD   ACTIVE SUB     DESCRIPTION
  -.mount                       loaded active mounted /
  boot.mount                    loaded active mounted /boot
  data-brick0.mount             loaded active mounted /data/brick0
  data-brick1.mount             loaded active mounted /data/brick1
  data-brick10.mount            loaded active mounted /data/brick10
  data-brick11.mount            loaded active mounted /data/brick11
  data-brick2.mount             loaded active mounted /data/brick2
  data-brick3.mount             loaded active mounted /data/brick3
  data-brick4.mount             loaded active mounted /data/brick4
  data-brick5.mount             loaded active mounted /data/brick5
  data-brick6.mount             loaded active mounted /data/brick6
  data-brick7.mount             loaded active mounted /data/brick7
  data-brick8.mount             loaded active mounted /data/brick8
  data-brick9.mount             loaded active mounted /data/brick9
  dev-hugepages.mount           loaded active mounted Huge Pages File System
  dev-mqueue.mount              loaded active mounted POSIX Message Queue File System
● disk10.mount                  loaded failed failed  /disk10
● disk11.mount                  loaded failed failed  /disk11
● disk12.mount                  loaded failed failed  /disk12
● disk2.mount                   loaded failed failed  /disk2
● disk3.mount                   loaded failed failed  /disk3
● disk4.mount                   loaded failed failed  /disk4
● disk5.mount                   loaded failed failed  /disk5
● disk6.mount                   loaded failed failed  /disk6
● disk7.mount                   loaded failed failed  /disk7
● disk8.mount                   loaded failed failed  /disk8
● disk9.mount                   loaded failed failed  /disk9
● home-t4.mount                 loaded failed failed  /home/t4
  home.mount                    loaded active mounted /home
  proc-sys-fs-binfmt_misc.mount loaded active mounted Arbitrary Executable File Formats File System
  sys-fs-fuse-connections.mount loaded active mounted FUSE Control File System
  sys-kernel-config.mount       loaded active mounted Configuration File System
  sys-kernel-debug.mount        loaded active mounted Debug File System

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.

33 loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.

• 检查 data-brick0.mount unit:

标准方法

对应于 systemd-fstab-generator 自动生成的 .mount unit文件，不需要手工去停止或删除，只需要正确修改 /etc/fstab ，然后执行

执行 daemon-reload 刷新

systemctl daemon-reload

就可以完全同步刷新配置。之后就可以手工 umount 挂载文件系统以及做磁盘初始化了

上述步骤非常重要 否则直接umount曾经配置过 /etc/fstab 挂载配置的文件系统，都会遇到反复自动挂载。一定要遵循 Systemd挂载文件系统(自动) 经验教训