Tasks

Reset root password

https://www.unixmen.com/reset-root-password-centos-7/

Get version

[root@node01 ~]# rpm --query centos-release
centos-release-7-4.1708.el7.centos.x86_64

SSH

yum -y install openssh-server openssh-clients
systemctl start sshd

Development tools

yum groupinstall "Development Tools"

EPEL repository

Extra Packages for Enterprise Linux (or EPEL) is a Fedora Special Interest Group that creates, maintains, and manages a high quality set of additional packages for Enterprise Linux, including, but not limited to, Red Hat Enterprise Linux (RHEL), CentOS and Scientific Linux (SL), Oracle Linux (OL).

yum -y install epel-release
yum repolist

Time

Replacement for ntp/ntpdate

yum install chrony

source: https://www.thegeekdiary.com/centos-rhel-7-configuring-ntp-using-chrony/

Set timezone

timedatectl list-timezones
timedatectl set-timezone Europe/Berlin

Networking

Interfaces configuration are in /etc/sysconfig/network-scripts/

Samba

yum install samba samba-client

DKMS

Remove conflicting packages:

yum remove ipa-common ipa-common-client ipa-client

Install DKMS:

yum install kernel-debug-devel dkms

From: https://www.titan.tw/web/anyplaceusb/InstallingDMKSonRedHatCentos.html

Update

wget 'http://mirror.centos.org/centos/8-stream/BaseOS/x86_64/os/Packages/centos-gpg-keys-8-2.el8.noarch.rpm'
rpm -i 'centos-gpg-keys-8-2.el8.noarch.rpm'
dnf --disablerepo '*' --enablerepo=extras swap centos-linux-repos centos-stream-repos
yum install --enablerepo=extras epel-release

No URLs in mirrorlist

When a version isn’t supported anymore, its files get moved to an archive, the vault, so the addresses have to be updated:

sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-*
sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g' /etc/yum.repos.d/CentOS-*

Grub

Grub cannot discover a windows installation if it’s booting differently (both windows and linux have to boot with MBR or EFI, no mix). In /etc/default/grub :

GRUB_DISABLE_OS_PROBER=false

For os-prober to work (it seems that) you need to be able to mount windows partitions (NTFS) and maybe even need to mount them (although this wasn’t needed with an EFI install):

yum install ntfs-3g os-prober

Update grub:

grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg

https://wiki.centos.org/HowTos/Grub2

Concepts

Alternatives

https://linux.die.net/man/8/update-alternatives