最开始，干净的新系统一共占硬盘 1.8G 的容量。使用yum命令安装如下程序：

yum update
yum upgrade

yum install gcc (already installed, actually do nothing)
yum install gcc-c++ gcc-gfortran

yum install ImageMagick

yum install lftp
yum install mc tree htop
yum install bzip2 (for install anaconda.sh)

yum install w3m
yum install httpd
    vi /etc/httpd/conf/httpd.conf ---> LISTEN 8000
    vi /etc/httpd/conf.d/userdir.conf ---> comment out "UserDir disabled"; uncomment "UserDir public_html"
    systemctl status  httpd.service
    systemctl start   httpd.service
    systemctl enable  httpd.service
    systemctl restart httpd.service

yum install netcdf nco ncl ncview grads

The clean OS occupies 1.8G at the very beginning!!!

yum update
yum upgrade

yum install gcc (already installed, actually do nothing)
yum install gcc-c++ gcc-gfortran

yum install ImageMagick

yum install lftp
yum install mc tree htop
yum install bzip2 (for install anaconda.sh)

yum install w3m
yum install httpd
vi /etc/httpd/conf/httpd.conf ---> LISTEN 8000
vi /etc/httpd/conf.d/userdir.conf ---> comment out "UserDir disabled"; uncomment "UserDir public_html"
systemctl status  httpd.service
systemctl start   httpd.service
systemctl enable  httpd.service
systemctl restart httpd.service

yum install netcdf nco ncl ncview grads

wget https://mirrors.tuna.tsinghua.edu.cn/anaconda/archive/Anaconda3-5.3.1-Linux-x86_64.sh
then install Anaconda3-5.3.1-Linux-x86_64.sh at /opt/anaconda3-3.5.1
Before:
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1        40G  2.8G   35G   8% /
After:
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1        40G  6.0G   32G  16% /
move 'conda init' code from /root/.bashrc to /etc/bashrc for ALL USERS like:
####################################
# added by Anaconda3 5.3.1 installer
# >>> conda init >>>
# !! Contents within this block are managed by 'conda init' !!
__conda_setup="$(CONDA_REPORT_ERRORS=false '/opt/anaconda3-5.3.1/bin/conda' shell.bash hook 2> /dev/null)"
if [ $? -eq 0 ]; then
    \eval "$__conda_setup"
else
    if [ -f "/opt/anaconda3-5.3.1/etc/profile.d/conda.sh" ]; then
        . "/opt/anaconda3-5.3.1/etc/profile.d/conda.sh"
        CONDA_CHANGEPS1=true conda activate base
    else
        \export PATH="/opt/anaconda3-5.3.1/bin:$PATH"
    fi
fi
unset __conda_setup
# <<< conda init <<<
####################################
generate a conda list in /opt/anaconda3-5.3.1/condalist-20190307 by 'conda list'
remove the original installer file to save 638M disk space.

add lines at the end of /etc/vimrc:
########################
"set encoding=utf-8
"set number
set tabstop=2
"set expandtab
set autoindent

set encoding=UTF-8              to ensure Chinese input in vim
set fileencoding=UTF-8
########################

yum install php php-pdo
========================================================================================================================
 Package                       Arch                      Version                          Repository               Size
========================================================================================================================
Installing:
 php                           x86_64                    5.4.16-46.el7                    base                    1.4 M
 php-pdo                       x86_64                    5.4.16-46.el7                    base                     99 k
Installing for dependencies:
 libzip                        x86_64                    0.10.1-8.el7                     base                     48 k
 php-cli                       x86_64                    5.4.16-46.el7                    base                    2.7 M
 php-common                    x86_64                    5.4.16-46.el7                    base                    565 k

Transaction Summary
========================================================================================================================
Install  2 Packages (+3 Dependent packages)

SINCE THIS DEFAULT VERSION IS PHP5.4, WAY TOO OLD FOR MEDEAWIKI, I HAVE TO REMOVE THEM BY...
yum erase php php-pdo php-cli php-common


===============================================================================
Install MediaWiki (Ref: https://www.tecmint.com/install-mediawiki-on-centos-7/)
===============================================================================
yum install http://rpms.remirepo.net/enterprise/remi-release-7.rpm
yum install epel-release
yum install yum-utils
yum-config-manager --enable remi-php73
yum install php php-pdo php-gd php-mbstring php-xml php-intl
systemctl restart httpd

chown -R apache:apache /var/www/html/mediawiki-1.33.0/
chown -R apache:apache /var/www/html/wiki
chmod 755 /var/www/html/mediawiki-1.33.0/
chmod 755 /var/www/html/wiki/
===============================================================================

Edit /etc/php.ini:
upload_max_filesize 100M (original=2M)
post_max_size 128M (original=8M)


===================================
Install DokuWiki (as group website)
AN EASY JOB
June 21, 2020
at /var/var/html/group
take a look at readme.xwen there

modify /etc/php.ini so as to allow upload big file in MediaManager
upload_max_filesize = 500M (from 100M)
post_max_size = 500M (from 128M)
===================================

yum update on June 21, 2020

2019年3月，闻新宇在aliyun上购买了一个为期3年的云主机，然后购买并绑定在了pkumet.live域名上。出于安全和稳定的考虑，这台云主机运行CentOS 7（2019年9月已经释放了CentOS 8，未升级）。主机硬件参数如下：

• 1 Processor
• 1G RAM
• 40G Hard drive