我目前正在尝试设置OBS Studio 中的虚拟摄像头在我的 Ubuntu 20.04 虚拟机 (DigitalOcean droplet) 上安装该v4l2loopback-dkms模块。但是，尽管虚拟相机按钮出现在 OBS 软件中，但单击它没有任何作用，如本文所述Stack Overflow 问题。这是我安装模块时发生的日志v4l2loopback：
ramy@opal-cafe:~$ sudo apt -y install v4l2loopback-dkms v4l2loopback-utils
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed: [ABRIDGED]
Suggested packages: [ABRIDGED]
The following NEW packages will be installed: [ABRIDGED]
0 upgraded, 38 newly installed, 0 to remove and 65 not upgraded.
Need to get 37.6 MB of archives.
After this operation, 173 MB of additional disk space will be used [ABRIDGED]
Fetched 37.6 MB in 1s (33.1 MB/s)
Extracting templates from packages: 100%
[ABRIDGED]
Setting up build-essential (12.8ubuntu1.1) ...
Setting up v4l2loopback-dkms (0.12.3-1ubuntu0.4) ...
Loading new v4l2loopback-0.12.3 DKMS files...
Building for 5.4.0-107-generic
Building initial module for 5.4.0-107-generic
Can't load /var/lib/shim-signed/mok/.rnd into RNG
139665634772288:error:2406F079:random number generator:RAND_load_file:Cannot open file: ../crypto/rand/randfile.c:98:Filename=/var/lib/shim-signed/mok/.rnd
Generating a RSA private key
............................................................+++++
...............................+++++
writing new private key to '/var/lib/shim-signed/mok/MOK.priv'
-----
EFI variables are not supported on this system
/sys/firmware/efi/efivars not found, aborting.
Done.
v4l2loopback.ko:
Running module version sanity check.
- Original module
- No original module exists within this kernel
- Installation
- Installing to /lib/modules/5.4.0-107-generic/updates/dkms/
depmod...
DKMS: install completed.
Processing triggers for libc-bin (2.31-0ubuntu9.7) ...
Processing triggers for man-db (2.9.1-1) ...
在以不同的方式卸载并重新安装v4l2loopback模块和 OBS Studio 几次后sudo modprobe v4l2loopback，我尝试了通过以下方式禁用安全启动：此方法。但是，当我尝试使用 检查安全启动状态时mokutil --sb-state，遇到此错误：
EFI variables are not supported on this system.
禁用安全启动的其他建议方法是从 BIOS 禁用它，但我不确定如何访问它，因为这是一台虚拟机（我使用 xrdp 和 Gnome 桌面来获取 GUI）。如果有人对我下一步该做什么有任何建议，请告诉我 - 我对 Ubuntu 还很陌生，而且是盲目入门。
在此添加后续内容：当我运行时sudo modprobe v4l2loopback，出现此错误：
modprobe: ERROR: could not insert 'v4l2loopback': Unknown symbol in module, or unknown parameter (see dmesg)