You could try using --skip-broken to work around the problem问题

 经常在yum update的时候遇到类似与这样的问题：

Error: Package:  *****************************
 Requires: ******************************
 Removing:  xxxxxxxxxxx.x86_64   (@rpmforge)   ****** 
 Updated By:   *******-*****-***********    Not find                                             
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

如：

[[email protected] ~]# yum install openssh-clients
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package openssh-clients.x86_64 0:5.3p1-84.1.el6 will be installed
--> Processing Dependency: openssh = 5.3p1-84.1.el6 for package: openssh-clients-5.3p1-84.1.el6.x86_64
--> Processing Dependency: libedit.so.0()(64bit) for package: openssh-clients-5.3p1-84.1.el6.x86_64
--> Running transaction check
---> Package libedit.x86_64 0:2.11-4.20080712cvs.1.el6 will be installed
---> Package openssh-clients.x86_64 0:5.3p1-84.1.el6 will be installed
--> Processing Dependency: openssh = 5.3p1-84.1.el6 for package: openssh-clients-5.3p1-84.1.el6.x86_64
--> Finished Dependency Resolution
Error: Package: openssh-clients-5.3p1-84.1.el6.x86_64 (c6-media)
           Requires: openssh = 5.3p1-84.1.el6
           Installed: openssh-5.3p1-123.el6_9.x86_64 (@base)
               openssh = 5.3p1-123.el6_9
           Available: openssh-5.3p1-84.1.el6.x86_64 (c6-media)
               openssh = 5.3p1-84.1.el6
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

解决办法：
将xxxxxxx-xxxxx-xxxx.x86_64卸载掉： yum remove xxxxx-xxxxx-xxxxxxx.x86_64
然后就可以yum update了!
应该是xxxxxxx-xxxxx-xxxxxxx.x86_64的epel更新源找不到，导致整个yum update不能用。
如果需要的话再将卸载掉的xxxxxx(去掉版本号等部分(-xxxxx-xxxxxxx)，重新索源安装，尽量避免再次导致同源找不到的问题）重新安装： yum install xxxxxx