Deploy, configure, and maintain systems Flashcards
cron order
# For details see man 4 crontabs # Example of job definition: # .---------------- minute (0 - 59) # | .------------- hour (0 - 23) # | | .---------- day of month (1 - 31) # | | | .------- month (1 - 12) OR jan,feb,mar,apr ... # | | | | .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue ... # | | | | | # * * * * * user-name command to be executed
how to start a service
systemctl start httpd
how to stop a service
systemctl stop httpd
how to make a service start automatically on startup
systemctl enable httpd
how to configure the system to boot into a specific target automatically
systemctl set-default multi-user.target
how to see all time zones
timedatectl list-timezones
how to set time zone to specific zone
timedatectl set-timezone America/Chicago
how to set time to specific time
timedatectl set-time 9:00:00
how to set ntp
timedatectl set-ntp true
need to double check what this actually does
how to see the sources for chrony
chronyc sources -v
how to install a software package
yum install package
how to search for a software package
yum search package
how to delete a software package
yum remove package
how to add a yum repository source
yum config-manager –add-repo=”https://dl.fedoraproject.org/pub/epel/8/Everything/x86_64/”
how to enable a disabled yum repository
yum config-manager –enable rhel-8-server-debug-rpms
how to view all yum repositories
yum repolist all
how to install a software package that is not signed
yum install –nogpgcheck package
how to update all packages on the system
yum update
how to update just packages that have security issues
yum update –security
how to view a list of all packages installed on the system
yum list installed
how to view all the past successful yum runs
yum history
how to revert a yum run
yum history undo 100
100 is the number of the run you want to undo, this can be found by running yum history
how to install a module
yum module install package
how to remove a module
yum module remove package
