CentOS 7 运行“ yum update”命令时，出现以下错误消息：

error: rpmdb: BDB0113 Thread/process 2196/139984719730496 failed: BDB1507 Thread died in Berkeley DB library
error: db5 error(-30973) from dbenv->failchk: BDB0087 DB_RUNRECOVERY: Fatal error, run database recovery
error: cannot open Packages index using db5 - (-30973)
error: cannot open Packages database in /var/lib/rpm
CRITICAL:yum.main:
Error: rpmdb open failed

好像YUM坏了。
我无法运行任何yum命令。
我以前从未遇到过此错误，而且我也不知道该怎么办。
因此，我前往CentOS论坛，希望找到合适的解决方案来解决此问题。
在论坛上进行几次搜索后，幸运的是我找到了解决方法。
如果我们遇到此问题，请无所事事，然后执行以下步骤。

解决 "Error: rpmdb open failed" 错误

首先以root用户身份使用命令备份rpm数据库：

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

然后，运行以下命令：

# yum clean all

现在，再次运行更新：

# yum update
Loaded plugins: fastestmirror
Cleaning repos: base epel extras updates
Cleaning up everything
Cleaning up list of fastest mirrors
[Hyman@theitroad ~]# yum update
Loaded plugins: fastestmirror
base | 3.6 kB 00:00 
epel/x86_64/metalink | 5.0 kB 00:00 
epel | 4.3 kB 00:00 
extras | 3.4 kB 00:00 
updates | 3.4 kB 00:00 
(1/7): base/7/x86_64/group_gz | 155 kB 00:02 
(2/7): epel/x86_64/group_gz | 170 kB 00:04 
(3/7): extras/7/x86_64/primary_db | 191 kB 00:12 
(4/7): epel/x86_64/updateinfo | 809 kB 00:21 
(5/7): base/7/x86_64/primary_db | 5.6 MB 00:26 
(6/7): epel/x86_64/primary_db | 4.8 MB 00:46 
(7/7): updates/7/x86_64/primary_db | 7.8 MB 00:50 
Determining fastest mirrors
 * base: mirror.ehost.vn
 * epel: repo.ugm.ac.id
 * extras: mirror.ehost.vn
 * updates: mirror.dhakacom.com
Resolving Dependencies
--> Running transaction check
---> Package NetworkManager.x86_64 1:1.4.0-19.el7_3 will be updated
---> Package NetworkManager.x86_64 1:1.4.0-20.el7_3 will be an update
---> Package NetworkManager-adsl.x86_64 1:1.4.0-19.el7_3 will be updated
[...]
--> Finished Dependency Resolution
Dependencies Resolved
================================================================================
 Package Arch Version Repository Size
================================================================================
Installing:
 kernel x86_64 3.10.0-514.26.2.el7 updates 37 M
 python2-libcomps x86_64 0.1.8-3.el7 epel 46 k
 replacing python-libcomps.x86_64 0.1.6-13.el7
Updating:
 NetworkManager x86_64 1:1.4.0-20.el7_3 updates 2.5 M
 NetworkManager-adsl x86_64 1:1.4.0-20.el7_3 updates 146 k
 NetworkManager-bluetooth x86_64 1:1.4.0-20.el7_3 updates 165 k
 NetworkManager-glib x86_64 1:1.4.0-20.el7_3 updates 385 k
 NetworkManager-libnm x86_64 1:1.4.0-20.el7_3 updates 443 k
 NetworkManager-team x86_64 1:1.4.0-20.el7_3 updates 147 k
 python-perf x86_64 3.10.0-514.26.2.el7 updates 4.0 M
 sudo x86_64 1.8.6p7-23.el7_3 updates 735 k
 systemd x86_64 219-30.el7_3.9 updates 5.2 M
 systemd-libs x86_64 219-30.el7_3.9 updates 369 k
 systemd-sysv x86_64 219-30.el7_3.9 updates 64 k
 tuned noarch 2.7.1-3.el7_3.2 updates 210 k
 xfsprogs x86_64 4.5.0-10.el7_3 updates 895 k
Removing:
 kernel x86_64 3.10.0-123.el7 @anaconda 127 M
Transaction Summary
================================================================================
Install 2 Packages
Upgrade 46 Packages
Remove 1 Package
Total download size: 84 M
Is this ok [y/d/N]: y

我键入y继续更新。
一切都按预期工作。

最后，我使用以下命令清除了备份：

# rm -i /tmp/__db*