在执行回退重启时，系统卡住一直处于重启状态，执行强制重启后系统进入救援模式，在救援模式中将一台正常系统的/etc/os-release拷贝到待升级机器后系统恢复，但系统并未回退完成，yum和rpm无法使用,哪位大佬遇到过类似的问题呢？或者是否可以将系统再次进行回退呢？
yum报错：
There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:
/usr/lib64/librpm.so.3: undefined symbol: rpm_execcon
Please install a package which provides this module, or
verify that the module is installed correctly.
It’s possible that the above module doesn’t match the
current version of Python, which is:
2.7.5 (default, Aug 4 2017, 00:39:18)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-16)]
If you cannot solve this problem yourself, please go to
the yum faq at:
http://yum.baseurl.org/wiki/Faq
rpm报错：
rpm:/usr/lib64/liblzma.so.5: version ‘XZ_5.2’ not found (required by /usr/lib64/librpmio.so.9)