Hello,
Is there any way to turn off the automatic directory (directories) creation during mount unit start/run? To make the [auto-generated] mount unit behave the same as the mount command - to end with an error?
- from the systemd.mount man page:
What=
Takes an absolute path of a device node, file or other resource to mount. See mount(8) for details. If this refers to a device node, a dependency on the respective device unit is automatically created. (See systemd.device(5) for more information.)
This option is mandatory.
Where=
Takes an absolute path of a directory of the mount point. If the mount point does not exist at the time of mounting, it is created. This string must be reflected in the unit filename. (See above.) This option is mandatory.
Takes an absolute path of a device node, file or other resource to mount. See mount(8) for details. If this refers to a device node, a dependency on the respective device unit is automatically created. (See systemd.device(5) for more information.)
This option is mandatory.
Where=
Takes an absolute path of a directory of the mount point. If the mount point does not exist at the time of mounting, it is created. This string must be reflected in the unit filename. (See above.) This option is mandatory.
- example:
- fstab:
/mnt/x /mnt/y none bind 0 0
- commands:
# systemctl daemon-reload
# systemctl --version
systemd 250 (v250.8-1.fc36)
systemd 250 (v250.8-1.fc36)
# ls -1 /mnt
# mount /mnt/y
mount: /mnt/y: mount point does not exist.
dmesg(1) may have more information after failed mount system call.
mount: /mnt/y: mount point does not exist.
dmesg(1) may have more information after failed mount system call.
# ls -1 /mnt
# systemctl cat mnt-y.mount
# /run/systemd/generator/mnt-y.mount
# Automatically generated by systemd-fstab-generator
[Unit]
Documentation=man:fstab(5) man:systemd-fstab-generator(8)
SourcePath=/etc/fstab
Before=local-fs.target
[Mount]
What=/mnt/x
Where=/mnt/y
Type=none
Options=bind
# /run/systemd/generator/mnt-y.mount
# Automatically generated by systemd-fstab-generator
[Unit]
Documentation=man:fstab(5) man:systemd-fstab-generator(8)
SourcePath=/etc/fstab
Before=local-fs.target
[Mount]
What=/mnt/x
Where=/mnt/y
Type=none
Options=bind
# systemctl start mnt-y.mount
# systemctl status mnt-y.mount
● mnt-y.mount - /mnt/y
Loaded: loaded (/etc/fstab; generated)
Active: active (mounted) since Thu 2022-10-20 09:01:05 CEST; 13s ago
Until: Thu 2022-10-20 09:01:05 CEST; 13s ago
Where: /mnt/y
What: /dev/mapper/vg_sys-lv_root
Docs: man:fstab(5)
man:systemd-fstab-generator(8)
Tasks: 0 (limit: 9333)
Memory: 16.0K
CPU: 6ms
CGroup: /system.slice/mnt-y.mount
Oct 20 09:01:05 demo-lab systemd[1]: Mounting mnt-y.mount - /mnt/y...
Oct 20 09:01:05 demo-lab systemd[1]: Mounted mnt-y.mount - /mnt/y.
● mnt-y.mount - /mnt/y
Loaded: loaded (/etc/fstab; generated)
Active: active (mounted) since Thu 2022-10-20 09:01:05 CEST; 13s ago
Until: Thu 2022-10-20 09:01:05 CEST; 13s ago
Where: /mnt/y
What: /dev/mapper/vg_sys-lv_root
Docs: man:fstab(5)
man:systemd-fstab-generator(8)
Tasks: 0 (limit: 9333)
Memory: 16.0K
CPU: 6ms
CGroup: /system.slice/mnt-y.mount
Oct 20 09:01:05 demo-lab systemd[1]: Mounting mnt-y.mount - /mnt/y...
Oct 20 09:01:05 demo-lab systemd[1]: Mounted mnt-y.mount - /mnt/y.
# mount | fgrep /mnt/y
/dev/mapper/vg_sys-lv_root on /mnt/y type ext4 (rw,relatime,seclabel,errors=remount-ro)
/dev/mapper/vg_sys-lv_root on /mnt/y type ext4 (rw,relatime,seclabel,errors=remount-ro)
# findmnt
TARGET SOURCE FSTYPE OPTIONS
...
├─/mnt/y /dev/mapper/vg_sys-lv_root[/mnt/x] ext4 rw,relatime,seclabel,errors=remount-ro
TARGET SOURCE FSTYPE OPTIONS
...
├─/mnt/y /dev/mapper/vg_sys-lv_root[/mnt/x] ext4 rw,relatime,seclabel,errors=remount-ro
...
# ls -1 /mnt
x
y
x
y
The systemd.mount unit created both directories - the destination directory /mnt/y (Where=) and also the source directory /mnt/x (What=). Additionally, this behavior for What= is not mentioned in the man page.
Thank you and with best regards,
