Linux多线程高速下载

有时候，我们用wget下载速度很慢，多数是几十K，下面我们来安装Axel。本文以CentOS 7.2 为例：
安装EPEL源

yum -y install epel-release

安装完上面的源后可以直接安装axel， 下面先来安装axel，命令为：

yum install  axel-2.4-9.el7.x86_64.rpm
rpm -ivh axel-2.4-9.el7.x86_64.rpm

运行下axel：

[root@DESKTOP-RCOA9NR]# axel
Usage: axel [options] url1 [url2] [url...]

--max-speed=x -s x Specify maximum speed (bytes per second) --num-connections=x -n x Specify maximum number of connections --output=f -o f Specify local output file --search[=x] -S [x] Search for mirrors and download from x servers --header=x -H x Add header string --user-agent=x -U x Set user agent --no-proxy -N Just don't use any proxy server --quiet -q Leave stdout alone --verbose -v More status information --alternate -a Alternate progress indicator --help -h This information --version -V Version information 
Visit http://axel.alioth.debian.org/ to report bugs

[root@DESKTOP-RCOA9NR soft]# axel -n 100 https://d1opms6zj7jotq.cloudfront.net/cpp/CLion-2016.1.1.tar.gz
初始化下载: https://d1opms6zj7jotq.cloudfront.net/cpp/CLion-2016.1.1.tar.gz
File size: 218442478 bytes
打开输出文件 CLion-2016.1.1.tar.gz.0
开始下载

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 也可以安装yum-axelget插件
 yum-axelget是EPEL提供的一个yum插件。默认的yum是单线程下载的，使用该插件后用yum安装软件时可以并行下载。yum-axelget插件原理是调用系统中的axel下载软件，然后根据软件包的大小自动设定线程数。在多线程操作时，还能避免因为线程数过多而导致服务器拒绝下载的问题，大大提高了软件的下载速度，减少了下载的等待时间。注意：通过下面这条安装命令，会同时安装axel下载软件

yum -y install yum-axelget

安装完插件过后，就可以快速的下载东西了，也可以更新系统：

yum clean all && yum makecache && yum -y update