在失败的＆＃34; yum更新＆＃34;之后，yum不起作用。
如果我尝试启动＆＃34; yum update＆＃34;结果我得到了：
# yum update
Loaded plugins: dellsysid, fastestmirror
Setting up Update Process
Loading mirror speeds from cached hostfile
YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
Eg. $releasever is not a valid release or hasnt been released yet/
removing mirrorlist with no valid mirrors: /var/cache/yum/x86_64/$releasever/base/mirrorlist.txt
Error: Cannot find a valid baseurl for repo: base
我下载并尝试安装＆＃34; centos-release＆＃34;但有错误：
# rpm -Uvh centos-release-6-6.el6.centos.12.2.x86_64.rpm
error: centos-release-6-6.el6.centos.12.2.x86_64.rpm: Header V3 RSA/SHA1 Signature, key ID c105b9de: BAD
error: centos-release-6-6.el6.centos.12.2.x86_64.rpm cannot be installed
最奇怪的是：
# rpm -q rpm
package rpm is not installed
如何解决问题并成功运行yum？
答案 0 :(得分：1)
对于6.6美分我也有同样的问题。因为yum变量$releasever未正确展开。发出以下命令：
$ python -c 'import yum, pprint; yb = yum.YumBase();pprint.pprint(yb.conf.yumvar, width=1)'
Loaded plugins: fastestmirror
{'arch': 'i686',
'basearch': 'i386',
'infra': 'stock',
'releasever': '$releasever',
'uuid': '19f9697d-6f4f-428a-848a-f317d7a880fb'}
在这种情况下，releaser的值应为6而不是$releasever。因此，只需将变量设置为正确的值，一切都会正常，使用以下命令：
echo 6 > /etc/yum/vars/releasever
现在您可以检查它是否有效：
$ python -c 'import yum, pprint; yb = yum.YumBase();pprint.pprint(yb.conf.yumvar, width=1)'
Loaded plugins: fastestmirror
{'arch': 'i686',
'basearch': 'i386',
'infra': 'stock',
'releasever': '6',
'uuid': '19f9697d-6f4f-428a-848a-f317d7a880fb'}
现在yum命令应该像魅力一样工作:)
答案 1 :(得分：0)