[CentOS] Problem running yum update command

[Darr247]

On 08 April 2014 @00:34 zulu, Frank Cox wrote:
> On Mon, 07 Apr 2014 20:27:17 -0400
> H wrote:
>
>> rpm --rebuilddb:
>>
>> rpmdb: unable to join the environment
> When I run that error message through google, this is the very first result:
>
> http://sysadmingear.blogspot.ca/2008/08/how-to-fix-rpmdb-unable-to-join.html
>

In case that blog site goes down in the future and you found this list's 
archives in google, the recommended fix there is deleting any files 
locking the RPM database.
e.g.
# rm -f /var/lib/rpm/__db*

Or, from user level
$ sudo rm -f /var/lib/rpm/__db*
or
$ su -c rm -f /var/lib/rpm/__db*

Then use the rpm --rebuilddb command again to rebuild the database, 
which could have been corrupted during the same crash that left the 
(typically zero-byte) semaphore file[s] as detritus.