前提：服務器中已安裝了cuda-9.0
接下來安裝cuda-9.2
1. 下載cuda-9.2
選擇cuda版本
https://developer.nvidia.com/cuda-toolkit-archive
選擇平台
安裝
安裝過程（出現more [0%]要按回車）
摘自：https://blog.csdn.net/ksws0292756/article/details/80120561
#先執行下面的命令安裝相關依賴，
#否則會出現`Missing recommended library`錯誤
sudo apt-get install freeglut3-dev build-essential libx11-dev libxmu-dev libxi-dev libgl1-mesa-glx libglu1-mesa libglu1-mesa-dev
sudo sh cuda_8.0.61_375.26_linux.run #開始安裝
#..一堆協議說明...
#直接按q退出協議說明.
zerozone@zerozone: accept/decline/quit: accept #接受協議
Install NVIDIA Accelerated Graphics Driver for Linux-x86_64 375.26?
y)es/(n)o/(q)uit: n #是否顯卡驅動包，由於已經安裝顯卡驅動，選擇n
Install the CUDA 8.0 Toolkit?
(y)es/(n)o/(q)uit: y #是否安裝工具包，選擇y
Enter Toolkit Location
[ default is /usr/local/cuda-8.0 ]: #工具包安裝地址，默認回車即可
Do you want to install a symbolic link at /usr/local/cuda?
(y)es/(n)o/(q)uit: y #添加鏈接**注意這個連接，如果你之前安裝過另一個版本的cuda，除非你確定想要用這個新版本的cuda，否則這里就建議選no，因為指定該鏈接后會將cuda指向這個新的版本**
Install the CUDA 8.0 Samples?
(y)es/(n)o/(q)uit: y #安裝樣例
Enter CUDA Samples Location
[ default is /root ]: #樣例安裝地址默認即可
# ***安裝信息***
Installing the CUDA Toolkit in /usr/local/cuda-8.0 ...
Missing recommended library: libXi.so
Missing recommended library: libXmu.so
#注意，這里出現了Missing recommended library錯誤，
#是因為博主在第一次安裝時，沒有添加最開始的那條安裝相關依賴的指令，
#之后我添加了依賴后，再次安裝，就沒有Missing錯誤了
Installing the CUDA Samples in /root ...
Copying samples to /root/NVIDIA_CUDA-8.0_Samples now...
Finished copying samples.
===========
= Summary =
===========
Driver: Not Selected
Toolkit: Installed in /usr/local/cuda-8.0
Samples: Installed in /root, but missing recommended libraries
Please make sure that
- PATH includes /usr/local/cuda-8.0/bin
- LD_LIBRARY_PATH includes /usr/local/cuda-8.0/lib64, or, add /usr/local/cuda-8.0/lib64 to /etc/ld.so.conf and run ldconfig as root
To uninstall the CUDA Toolkit, run the uninstall script in /usr/local/cuda-8.0/bin
Please see CUDA_Installation_Guide_Linux.pdf in /usr/local/cuda-8.0/doc/pdf for detailed information on setting up CUDA.
***WARNING: Incomplete installation! This installation did not install the CUDA Driver. A driver of version at least 361.00 is required for CUDA 8.0 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 /tmp/cuda_install_6388.log
# ***安裝完成***
2. 配置CUDA相關環境變量
打開/usr/local， 可以看到cuda9.2安裝包已存在
cuda是個軟連接，將原來的軟連接刪除，建立新的指向cuda-9.2的軟連接
sudo rm -rf cuda
sudo ln -s /usr/local/cuda-9.2 /usr/local/cuda
查看此時cuda指向：
修改~/.bashrc文件：
將終端關閉，開啟一個新的終端,輸入：
source ~/.bashrc
成功！ 查看nvcc版本：
若以后想要使用切換不同版本的cuda，只需
（1）將cuda的軟連接刪除，再重新建立指向新版本的cuda-x.x的軟連接
（2）打開新的終端執行source ~/.bashrc
即可。