运行：
yum install zlib
错误：Multilib version problems found. This often means that the root cause is something else and multilib version checking is just pointing out that there is a problem. Eg.:
1. You have an upgrade for zlib which is missing some dependency that another package requires. Yum is trying to solve this by installing an older version of zlib of the different architecture. If you exclude the bad architecture yum will tell you what the root cause is (which package requires what). You can try redoing the upgrade with--exclude zlib.otherarch ... this should give you an error message showing the root cause of the problem.
2. You have multiple architectures of zlib installed, but yum can only see an upgrade for one of those architectures.If you don't want/need both architectures anymore then you can remove the one with the missing update and everything will work.
3. You have duplicate versions of zlib installed already.You can use "yum check" to get yum show these errors.
...you can also use --setopt=protected_multilib=false to remove this checking, however this is almost never the correct thing to do as something else is very likely to go wrong (often causing much more problems).
保护多库版本：zlib-1.2.7-15.el7.x86_64 != zlib-1.2.7-13.el7.i686
解决：
yum install --setopt=protected_multilib=false zlib