axel插件是基于yum下的一个多线程下载插件，通过打开多个HTTP/FTP连接来将一个文件进行分段下载，从而达到加速下载的目的。对于下载大文件，该工具特别有用。可用于CentOS、RHEL、Fedora等使用yum的Linux发行版。暂时找不到rpm包，只能编译安装。使用Axel可以在低速网络环境里提高数倍的下载速度。
1 下载axel插件的rpm包
下载地址
如果为centos 5 64位系统的话 使用
如果为centos 6 64位系统 使用
2 安装rpm 包 rpm -ivh
可以直接运行命令安装
yum install axel
3 下载配置文件axelget.conf与axelget.py到yum里：
cd /etc/yum/pluginconf.d/
wget
也可以自己编辑，全文如下：
[main]
enabled=1
onlyhttp=1
enablesize=54000
cleanOnException=1
cd /usr/lib/yum-plugins/
wget
也可以自己编辑，全文如下：
from yum.plugins import PluginYumExit, TYPE_CORE, TYPE_INTERACTIVE
from urlparse import urljoin
import os,time
requires_api_version = '2.3'
plugin_type = (TYPE_CORE, TYPE_INTERACTIVE)
enablesize=300000
trymirrornum=-1
maxconn=10
httpdownloadonly=False
cleanOnException=0
def init_hook(conduit):
global enablesize,trymirrornum,maxconn,cleanOnException,httpdownloadonly
enablesize = conduit.confInt('main','enablesize',default=30000)
trymirrornum = conduit.confInt('main','trymirrornum',default=-1)
maxconn = conduit.confInt('main','maxconn',default=10)
httpdownloadonly=conduit.confBool('main','onlyhttp',default=False)
cleanOnException=conduit.confInt('main','cleanOnException',default=0)
return
def predownload_hook(conduit):
global enablesize,cleanOnException,httpdownloadonly
preffermirror=""
PkgIdx=0
TotalPkg=len(conduit.getDownloadPackages())
for po in (conduit.getDownloadPackages()):
PkgIdx+=1
if hasattr(po, 'pkgtype') and po.pkgtype == 'local':
continue
totsize = long(po.size)
ret = False
if totsize <= enablesize:
conduit.info(2, "Package %s download size %d less than %d,Skip plugin!" % (po.repo.id,totsize,enablesize))
continue
else:
conduit.info(2, "[%d/%d]Ok,we will try to use axel to download this big file:%d" % (PkgIdx,TotalPkg,totsize))
local = po.localPkg()
if os.path.exists(local):
if not os.path.exists(local+".st"):
fstate=os.stat(local)
if totsize == fstate.st_size:
conduit.info(2,"Target already exists,skip to next file!")
continue
localall = "%s %s" % (local,local+".st")
rmcmd = "rm -f %s" % (localall)
curmirroridx = 0
conduit.info(2,"Before we start,clean all the key files")
os.system(rmcmd)
connnum = totsize / enablesize
if connnum*enablesize<totsize:
connnum+=1
if connnum > maxconn:
connnum = maxconn
mirrors=[]
mirrors[:0]=po.repo.urls
if preffermirror != "":
mirrors[:0] = [preffermirror]
for url in mirrors:
if url.startswith("ftp://") and httpdownloadonly:
print "Skip Ftp Site:",url
continue
if url.startswith("file://"):
print "Skip Local Site:",url
continue
curmirroridx += 1
if (curmirroridx > trymirrornum) and (trymirrornum != -1):
conduit.info(2, "Package %s has tried %d mirrors,Skip plugin!" % (po.repo.id,trymirrornum))
break
remoteurl = "%s/%s" % (url,po.remote_path)
syscmd = "axel -a -n %s %s -o %s" % (connnum,remoteurl,local)
conduit.info(2, "Execute axel cmd:\n%s" % syscmd)
os.system(syscmd)
time.sleep(2)
if os.path.exists(local+".st"):
conduit.info(2,"axel exit by exception,let's try another mirror")
if cleanOnException:
conduit.info(2,"because cleanOnException is set to 1,we do remove key file first")
os.system(rmcmd)
continue
elif not os.path.exists(local):#this mirror may not update yet
continue
else:
ret = True
preffermirror=url
break
if not ret:
conduit.info (2,"try to run rm cmd:%s" % rmcmd)
os.system(rmcmd)
最后确认 /etc/yum.conf中plugins=1