Common Commands (CentOS 7)

Common commands for CentOS 7 specific Operating Systems are below

Basic Configuration

Query or System Locale localectl Display the Current Time and Date date timedatectl Sync Date and Time timedatectl Configure SSH /etc/ssh/ssh_config
/etc/ssh/sshd_config

Jobs and Services

List all Services systemctl -at service
ls /etc/systemd/system/*.service
ls /usr/lib/systemd/system/*.service
List Services that are Running systemctl -t service –state=active Start and Stop services. Replace with the name of the service systemctl start
systemctl stop Enable and Disable Services. Replace with the name of the service systemctl enable
systemctl to disable Check Service Status. Replace with the service name systemctl status. See if a Service is Enabled. Replace with the service name systemctl is-enabled Configure Logs /etc/rsyslog.conf
/etc/rsyslog.d/*.conf View Logs /var/log journalctl Find Files find Create Archive tar
cpio

Kernel, Boot, Hardware

Single user Rescue Mode append rd. a break or init=/bin/bash to kernel cmdline Power Off System poweroff
systemctl poweroff Halt System halt
systemctl halt Reboot System reboot
systemctl reboot Configure GRUB /etc/default/grub
grub2-mkconfig
grub-set-default View Kernel Parameters sysctl -a
cat /proc/cmdline Load Kernel Module modprobe View Kernel Version rpm -q kernel
uname -r

Software Management

Install Software yum install
yum group install View Software Info yum info
yum group info Update Software yum update Upgrade Software yum upgrade Configure Software Repositories /etc/yum.repos.d/*.repo Find Package Owning File rpm -qf filename
yum provides filename-glob View Software Version rpm -q packagename View Installed Software rpm -qa
yum list installed

User Management

Create User useradd Delete User userdel View or Change User Details usermod
/etc/passwd
vipw
id Create User Group groupadd Delete User Group groupdel Change Group Details groupmod
/etc/group Change User Password passwd Change User Permissions usermod
visudo Change Group Permissions groupmod
visudo Change Password Policy chage View User Sessions w

File Systems, Volumes and Disks

Create / Modify Disk Permissions fdisk
gdisk
parted
ssm create Format Disk Partitions mkswap Defragment Disk Space fsck Mount Storage mount
/etc/fstab Mount and Activate Swap /etc/fstab
swapon -a View Free Disk Space df Check or Repair File System fsck Change File Permissions chmod
chown
chgrp
umask Change File Attributes chattr Change Access Control List setfacl

Networking

Change Name Resolution /etc/hosts
/etc/resolv.conf Configure Hostname hostnamectl
/etc/hostname View Network Interface Information ip addr
teamdctl
bridge View Routes ip route Configure Routes ip route add Configure Firewall firewall-cmd View Ports / Sockets ss
lsof

Security and Identity

Configure Security System /etc/selinux/config chcon
restorecon
semanage
setsebool LDAP, SSSD authconfig
authconfig-tui Network Users getent

Resource Management

Change Process Priority nice
renice Change Process Run Location taskset Kill a Process kill
pkill View System Usage top
ps
ss
vmstat View Disk Usage df