centos yum fails installing anything or updating system - centos

Question

I am trying to install a package on CentOS, but it throws error when I run the "yum" command. The internet connection is working fine.
I try to yum clean all but problem persist.
Error:
[root#dcos-master3 ~]# yum install ntp
Loaded plugins: fastestmirror
One of the configured repositories failed (Unknown),
and yum doesn't have enough cached data to continue. At this point the only
safe thing yum can do is fail. There are a few ways to work "fix" this:
1. Contact the upstream for the repository and get them to fix the problem.
2. Reconfigure the baseurl/etc. for the repository, to point to a working
upstream. This is most often useful if you are using a newer
distribution release than is supported by the repository (and the
packages for the previous distribution release still work).
3. Run the command with the repository temporarily disabled
yum --disablerepo=<repoid> ...
4. Disable the repository permanently, so yum won't use it by default. Yum
will then just ignore the repository until you permanently enable it
again or use --enablerepo for temporary usage:
yum-config-manager --disable <repoid>
or
subscription-manager repos --disable=<repoid>
5. Configure the failing repository to be skipped, if it is unavailable.
Note that yum will try to contact the repo. when it runs most commands,
so will have to try and fail each time (and thus. yum will be be much
slower). If it is a very temporary problem though, this is often a nice
compromise:
yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true
Cannot find a valid baseurl for repo: base/$releasever/x86_64
My yum repolist is the next:
[root#dcos-master3 ~]# yum repolist list
Loaded plugins: fastestmirror
https://yum.dockerproject.org/repo/main/centos/%24releasever/repodata/repomd.xml: [Errno 14] HTTPS Error 403 - Forbidden
Trying other mirror.
To address this issue please refer to the below knowledge base article
https://access.redhat.com/solutions/69319
If above article doesn't help to resolve this issue please create a bug on https://bugs.centos.org/
repolist: 0
If I list the repolist:
[root#dcos-master3 ~]# yum repolist
Loaded plugins: fastestmirror
https://yum.dockerproject.org/repo/main/centos/%24releasever/repodata/repomd.xml: [Errno 14] HTTPS Error 403 - Forbidden
Trying other mirror.
To address this issue please refer to the below knowledge base article
https://access.redhat.com/solutions/69319
If above article doesn't help to resolve this issue please create a bug on https://bugs.centos.org/
repo id repo name status
base/$releasever/x86_64 CentOS-$releasever - Base 0
dockerrepo/$releasever Docker Repository 0
extras/$releasever/x86_64 CentOS-$releasever - Extras 0
updates/$releasever/x86_64 CentOS-$releasever - Updates 0
repolist: 0

Answer 1

BEFORE TRYING ANY OF THIS, HAVE A BACKUP OF YOUR MACHINE, YOU COULD DAMAGE YOUR OS MORE/COMPLETELY
It seems that your yum variable $releasever is somehow corrupt,
it usually is caused by missing centos-release package on the machine for some obscure reasons.
You can check if you have the package by:
rpm -qi centos-release
You will probably see:
"package centos-release is not installed"
First find out the exact centos version that you have by executing as root:
cat /etc/redhat-release
You will see something like this:
CentOS Linux release 7.3.1611 (Core)
You can fetch the centos-release package from repo by:
wget http://vault.centos.org/centos/7.3.1611/updates/x86_64/Packages/centos-release-7-3.1611.el7.centos.2.5.x86_64.rpm
Now run reinstall centos-release package via rpm:
sudo rpm -Uvh --replacepkgs centos-release-7-3.1611.el7.centos.2.5.x86_64.rpm
As next you can try to install something with yum and you might get:
[root#dcos-master3 ikerlan]# sudo yum install wget
error: db5 error(-30969) from dbenv->open: BDB0091 DB_VERSION_MISMATCH: Database environment version mismatch
error: cannot open Packages index using db5 - (-30969)
error: cannot open Packages database in /var/lib/rpm
CRITICAL:yum.main:
Error: rpmdb open failed
Now you can try to reboot the machine or try to use the following command to rebuild the rpm db:
rpm --rebuilddb

Answer 2

I came across the same issue while downloading some packages in centos 7. After days of search, I found the solution:
Go to the yum repo directory.
cd /etc/yum.repos.d.
Make a copy of the CentOS-Base.repo file.
cp CentOS-Base.repo CentOS-Base.repo.old
Edit the CentOS-Base.repo file. Comment mirrorlist and uncomment baseurl.
vi CentOS-Base.repo
[base]
name=CentOS-$releasever - Base
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os&infra=$infra
baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
Now when you use yum, do the following.
sudo yum --disablerepo=* --enablerepo=base install httpd
Likewise for yum update.
sudo yum --disablerepo=* --enablerepo=base install httpd
It should work now.

Answer 3

I ran into this problem when attempting to install MariaDB on CentOS 7. I was super frustrated and after much searching found the answer at this link.
Here is what fixed this problem for me. Run as root.
# yum --disablerepo "*" --enablerepo epel install [package]
# yum clean all
"epel" can be whatever repo you like, but this one worked for me. Place [package] in the command just as written, not what package you are trying to install.
After you run the above, exit root and run whatever install you were attempting before encountering the error.

Answer 4

I noticed that in the failing url, your $releasever is %24releasever, but it should be 7 or 7.14.xx. Please check your yum config file at /etc/yum/var, or search in every .repo file, to see what is its value. It may be corrupted.
See Red Hat documentation for more information about how to set these variables.
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/deployment_guide/sec-using_yum_variables

Answer 5

yum install http://rpms.remirepo.net/enterprise/remi-release-7.rpm -y
yum -y install yum-utils
yum-config-manager --enable remi-php74
Then proceed to your installation/updates/etc

Answer 6

Always make sure NAT is active on your centos7. Specially when there is a VMnet2 for host. Because sometimes VMNet2 can be active instead of NAT and because of that you will not be able to connect to the internet through centos7. This is just a one reason for getting that error.