执行yum遇到"Error: rpmdb open failed

在linux系统（rhel）执行yum安装包时，提示如下错误：

rpmdb: Thread/process 6539/140448388269824 failed: Thread died in Berkeley DB library
error: db3 error(-30974) from dbenv->failchk: DB_RUNRECOVERY: Fatal error, run database recovery
error: cannot open Packages index using db3 -  (-30974)
error: cannot open Packages database in /var/lib/rpm
CRITICAL:yum.main:

Error: rpmdb open failed

解决：
1、备份rpm数据库

mv /var/lib/rpm/__db* /tmp

2、清除缓存，重新更新

yum clean all
yum update

3、清理第一步的备份

rm -i /tmp/__db*

https://ostechnix.com/solve-error-rpmdb-open-failed-error-centos/