# Package Management

## Dependency Resolution Failure / Duplicate Packages
If e.g. an update attempt ends up in something like
```
# yum update
Loaded plugins: langpacks, search-disabled-repos
Resolving Dependencies
...
--> Finished Dependency Resolution
Error: Package: sssd-dbus-1.16.5-10.el7_9.12.x86_64 (@rhel7)
           Requires: sssd-common = 1.16.5-10.el7_9.12
           Removing: sssd-common-1.16.5-10.el7_9.12.x86_64 (@rhel7)
               sssd-common = 1.16.5-10.el7_9.12
           Updated By: sssd-common-1.16.5-10.el7_9.15.x86_64 (rhel7)
               sssd-common = 1.16.5-10.el7_9.15
           Removing: sssd-common-1.16.5-10.el7_9.13.x86_64 (@rhel7)
...
```
best check if one of these packages is twice listed as installed:
```
# rpm -qa sssd-common
sssd-common-1.16.5-10.el7_9.13.x86_64
sssd-common-1.16.5-10.el7_9.12.x86_64
```
Now you can try to remove one or both packages, maybe you need to remove also packages which depend on this one. Then install it again. 

## Berkley DB Issue
If the error message is
```
error: rpmdb: BDB0113 Thread/process 21389/140229907089216 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
```

then do 

```
mv /var/lib/rpm/__db* /tmp
yum clean all
```

## Rebuild RPM Database
When `yum`, `dnf` or `rpm` hang or have errors pointing to a problem with their database, then follow the
[Guide to rebuild a corrupted RPM database](https://www.tecmint.com/rebuild-corrupted-rpm-database-in-centos/)