我在 fstab nfs 挂载条目中使用“bg”选项，因为 nfs 共享在计算机启动时并不总是可用：
sal.fritz.box:/tank1_data /mnt/sal_data nfs fsc,nfsvers=4.2,nofail,bg 0 0
这将转换为以下 systemd“挂载”单元：
# /run/systemd/generator/mnt-sal_data.mount
# Automatically generated by systemd-fstab-generator
[Unit]
SourcePath=/etc/fstab
Documentation=man:fstab(5) man:systemd-fstab-generator(8)
[Mount]
Where=/mnt/sal_data
What=sal.fritz.box:/tank1_data
Type=nfs
TimeoutSec=infinity
Options=x-systemd.mount-timeout=infinity,retry=10000,fsc,nfsvers=4.2,nofail,bg,fg
我现在所期望的是，启动时“挂载”进程会等待，直到 nfs 共享变得可用。但是，设备启动后立即显示失败：
● mnt-sal_data.mount - /mnt/sal_data
Loaded: loaded (/etc/fstab; generated; vendor preset: disabled)
Active: failed (Result: exit-code) since Thu 2020-10-29 23:18:27 CET; 3min 8s ago
Where: /mnt/sal_data
What: sal.fritz.box:/tank1_data
Docs: man:fstab(5)
man:systemd-fstab-generator(8)
Tasks: 0
CGroup: /system.slice/mnt-sal_data.mount
Okt 29 23:18:27 hal2000 systemd[1]: Mounting /mnt/sal_data...
Okt 29 23:18:27 hal2000 systemd[1]: mnt-sal_data.mount: Mount process exited, code=exited status=32
Okt 29 23:18:27 hal2000 systemd[1]: Failed to mount /mnt/sal_data.
Okt 29 23:18:27 hal2000 systemd[1]: mnt-sal_data.mount: Unit entered failed state.
显然，在这种情况下，nfs 共享永远不会挂载。
但是，如果我手动重新启动挂载单元，一切都会按预期工作：挂载过程等待 nfs 共享的可用性...
● mnt-sal_data.mount - /mnt/sal_data
Loaded: loaded (/etc/fstab; generated; vendor preset: disabled)
Active: activating (mounting) since Thu 2020-10-29 23:56:19 CET; 9s ago
[...]
Process: 10713 ExecUnmount=/usr/bin/umount /mnt/sal_data -c (code=exited, status=0/SUCCESS)
Cntrl PID: 10833 (mount)
Tasks: 2
CGroup: /system.slice/mnt-sal_data.mount
├─10833 /usr/bin/mount sal.fritz.box:/tank1_data /mnt/sal_data -t nfs -o x-systemd.mount-timeout=infinity,retry=10000,fsc,nf>
└─10834 /sbin/mount.nfs sal.fritz.box:/tank1_data /mnt/sal_data -o rw,retry=10000,fsc,nfsvers=4.2,bg,fg
Okt 29 23:56:19 hal2000 systemd[1]: Mounting /mnt/sal_data...
...共享一旦可用，就会成功安装：
● mnt-sal_data.mount - /mnt/sal_data
Loaded: loaded (/etc/fstab; generated; vendor preset: disabled)
Active: active (mounted) since Thu 2020-10-29 23:59:44 CET; 5s ago
[...]
Process: 10713 ExecUnmount=/usr/bin/umount /mnt/sal_data -c (code=exited, status=0/SUCCESS)
Process: 10833 ExecMount=/usr/bin/mount sal.fritz.box:/tank1_data /mnt/sal_data -t nfs -o x-systemd.mount-timeout=infinity,retry=1000>
Tasks: 0
CGroup: /system.slice/mnt-sal_data.mount
Okt 29 23:56:19 hal2000 systemd[1]: Mounting /mnt/sal_data...
Okt 29 23:59:44 hal2000 systemd[1]: Mounted /mnt/sal_data.
我还更改了“nofail”选项：没有区别。我希望不需要手动重新启动。我想念什么？
我不想使用“自动挂载”功能，因为如果意外访问挂载点，这会导致系统临时挂起。
系统：openSUSE Leap 15.1，systemd 234
问候，斯文