1. 更改为清华源并更新软件列表和依赖项

https://mirrors.tuna.tsinghua.edu.cn/help/ubuntu/

# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-updates main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-backports main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-backports main restricted universe multiverse

# deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-security main restricted universe multiverse
# # deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-security main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu/ focal-security main restricted universe multiverse
# deb-src http://security.ubuntu.com/ubuntu/ focal-security main restricted universe multiverse

更新软件列表和必要的依赖项

sudo apt-get update		# 更新软件列表
sudo apt-get install g++		# 下载g++编译器
sudo apt-get install gcc		# 下载gcc编译器
sudo apt-get install make		# 下载GNU Make编译器
sudo apt-get install initramfs-tools   # 下载安装initramfs-tools

2. 安装CUDA

步骤一： 下载CUDA安装包

• 进行CUDA和cuDNN的选择，也可以直接根据官方推荐进行下载安装。
• 从Nvidia官网下载CUDA https://developer.nvidia.com/cuda-downloads
  下方链接，选择更多版本 https://developer.nvidia.com/cuda-toolkit-archive
  
• 接下来根据提示进行下载、安装

wget https://developer.download.nvidia.com/compute/cuda/11.8.0/local_installers/cuda_11.8.0_520.61.05_linux.run
sudo sh cuda_11.8.0_520.61.05_linux.run

步骤二： 安装CUDA安装包过程中的选择

• Do you accept the above EULA? (accept / decline / quit):
  是否接受最终用户许可协议，输入accept
  

• 回车键进行勾选，X就是选中，没有X就是没有选中，把安装驱动进行取消。之后向下键，回车确认
  

• 最后点击 install

• 出现了警告信息，对安装无影响

截图日志：

wit622@622:~/cuda$ sudo sh cuda_11.8.0_520.61.05_linux.run
[sudo] wit622 的密码： 
===========
= Summary =
===========

Driver:   Not Selected
Toolkit:  Installed in /usr/local/cuda-11.8/

Please make sure that
 -   PATH includes /usr/local/cuda-11.8/bin
 -   LD_LIBRARY_PATH includes /usr/local/cuda-11.8/lib64, or, add /usr/local/cuda-11.8/lib64 to /etc/ld.so.conf and run ldconfig as root

To uninstall the CUDA Toolkit, run cuda-uninstaller in /usr/local/cuda-11.8/bin
***WARNING: Incomplete installation! This installation did not install the CUDA Driver. A driver of version at least 520.00 is required for CUDA 11.8 functionality to work.
To install the driver using this installer, run the following command, replacing <CudaInstaller> with the name of this run file:
    sudo <CudaInstaller>.run --silent --driver

Logfile is /var/log/cuda-installer.log

也可以进入日志进行查看（位置如下）：

 /var/log/cuda-installer.log

步骤三： 配置CUDA环境

sudo  vim ~/.bashrc

• 在bashrc文件最下方，添加下入代码
• （ps：这边需要注意cuda的版本，版本不同，路径的命名需修改）

export PATH=$PATH:/usr/local/cuda-11.8/bin
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/cuda-11.8/lib64

• 更新环境

source ~/.bashrc

• 测试CUDA是否安装成功

nvcc -V

输出下述结果，表示安装成功:

wit622@622:~/cuda$ nvcc -V
nvcc: NVIDIA (R) Cuda compiler driver
Copyright (c) 2005-2022 NVIDIA Corporation
Built on Wed_Sep_21_10:33:58_PDT_2022
Cuda compilation tools, release 11.8, V11.8.89
Build cuda_11.8.r11.8/compiler.31833905_0

3. 安装cuDNN

步骤一：下载cuDNN包

https://developer.nvidia.com/rdp/cudnn-archive

• 例如这边选择了Download cuDNN v8.8.1 (March 8th, 2023), for CUDA 11.x
• 点击Local Installer for Linux x86_64 (Tar)即可下载压缩包
  
• 将压缩包，放入自定义路径后，输入命令进行解压

tar -xvf cudnn-linux-x86_64-8.8.1.3_cuda11-archive.tar.xz 

• 解压后，输入命令，讲cuDNN对应文件拷贝至CUDA指定路径。

wit622@622:~/下载$ cd cudnn-linux-x86_64-8.8.1.3_cuda11-archive/
wit622@622:~/下载/cudnn-linux-x86_64-8.8.1.3_cuda11-archive$ ls
include  lib  LICENSE

sudo cp include/cudnn*.h /usr/local/cuda-11.8/include
sudo cp lib/libcudnn* /usr/local/cuda-11.8/lib64
sudo chmod a+r /usr/local/cuda-11.8/include/cudnn*.h /usr/local/cuda-11.8/lib64/libcudnn*

4. CUDA版本切换

因为后续部分项目，用的库对应的CUDA不同，无需进行修改，修改环境CUDA路径即可。例如需要11.1的CUDA，可通过修改bashrc进行修改

sudo vim ~/.bashrc

将原先的cuda-11.8注释掉，添加cuda-11.1新的环境设置，即可

# cuda-11.8
# export PATH=$PATH:/usr/local/cuda-11.8/bin
# export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/cuda-11.8/lib64

# cuda-11.1
export PATH=$PATH:/usr/local/cuda-11.1/bin
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/cuda-11.1/lib64