Mengatasi error CentOS 7 Could not retrieve mirrorlist (tidak bisa update)

Berikut cara mengatasi error CentOS 7 tidak bisa update dengan keterangan Errornya seperti ini, padahal koneksi internet server atau VPS lancar via CURL maupun ping ke server mirror.

Loaded plugins: fastestmirror
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os error was
12: Timeout on http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os: (28, 'Connection timed out after 30189 milliseconds')

One of the configured repositories failed (Unknown),
and yum doesn't have enough cached data to continue. At this point the only<br>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. Disable the repository, 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>

 4. 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/7/x86_64

Ganti mirrorlist ke baseurl

cd /etc/yum.repos.d/

Kemudian edit file CentOS-Base.repo

nano CentOS-Base.repo

Beri komentar # pada setiap mirrorlist dan hapus komentar # pada baseurl

Update system

yum update -y

Saat update akan banyak keterangan error. Error tersebut kemungkinan dikarenakan versi curl.

Upgrade Curl

Segera upgrade versi curl terbaru caranya ikuti tutorial -> Cara upgrade Curl di CentOS 7

Restart

reboot

Ulangi update system

Setelah upgrade cURL, ulangi kembali update system dengan perintah:

yum update -y

Selesai, semoga bermanfaat.