YumRepo Error: All mirror URLs are not using

YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
Eg. $releasever is not a valid release or hasnt been released yet/
removing mirrorlist with no valid mirrors: /var/cache/yum/base/mirrorlist.txt
Error: Cannot retrieve repository metadata (repomd.xml) for repository: base. Please verify its path and try again

从字面意思是看是不能正确连接到http或是ftp的真实地址上。

1.有可能是防火墙阻碍了出网http请求或是ftp请求，请检查网关防火墙。

2.有可能是dns不对，无法正常解析，换成8.8.4.4

3.系统取不到Release号

我这里碰到真正的原因是就是3，系统读取不到Release号。

正常一般可以看到版本号

# lsb_release -a
LSB Version:  :core-4.0-amd64:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-noarch
Distributor ID: CentOS
Description:  CentOS release 6.2 (Final)
Release:  6.2Codename:  Final

但是部署的环境上确是，

LSB Version:  :core-4.0-amd64:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-noarch
Distributor ID: n/a
Description: n/a
Release:  n/a
Codename:  n/a

而/etc/yum.repos.d下的*.repo源文件中都是baseurl都是带变量的

baseurl=http://mirrors.163.com/centos/$releasever/contrib/$basearch/

所以yum去尝试读取xml文件自然失败了。

# wget http://mirrors.163.com/centos/%releasever/os/x86_64/repodata/repomd.xml
--2013-01-24 10:50:10-- http://mirrors.163.com/centos/%releasever/os/x86_64/repodata/repomd.xml
Resolving mirrors.163.com... 123.58.173.89, 123.58.173.106
Connecting to mirrors.163.com|123.58.173.89|:80... connected.
HTTP request sent, awaiting response... 404 Not Found
2013-01-24 10:50:11 ERROR 404: Not Found.

所以需要修改*.repo源文件中将$releasever变量全替换成6即可正常yum了。

cat /etc/yum.repos.d/CentOS6-Base-163.repo
# CentOS-Base.repo
[base]
name=CentOS-6 - Base - 163.com
baseurl=http://mirrors.163.com/centos/6/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=os
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6

#released updates
[updates]
name=CentOS-6 - Updates - 163.com
baseurl=http://mirrors.163.com/centos/6/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=updates
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6

#additional packages that may be useful
[extras]
name=CentOS-6 - Extras - 163.com
baseurl=http://mirrors.163.com/centos/6/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=extras
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6

#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-6 - Plus - 163.com
baseurl=http://mirrors.163.com/centos/6/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6

#contrib - packages by Centos Users
[contrib]
name=CentOS-6 - Contrib - 163.com
baseurl=http://mirrors.163.com/centos/6/contrib/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=contrib
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6

看看这次更新缓存就成功了。

# yum makecache
base                 | 3.7 kB  00:00
base/filelists_db    | 5.9 MB  00:04
base/primary_db      | 4.5 MB  00:03
base/other_db        | 2.6 MB  00:01
base/group_gz        | 211 kB  00:00
extras               | 3.5 kB  00:00
extras/filelists_db  |  13 kB  00:00
extras/prestodelta   | 1.3 kB  00:00
extras/primary_db    |  23 kB  00:00
extras/other_db      | 7.9 kB  00:00
updates              | 3.5 kB  00:00
updates/filelists_db | 3.6 MB  00:02
updates/prestodelta  | 642 kB  00:00
updates/primary_db   | 4.6 MB  00:03
updates/other_db     | 473 kB  00:00