Rocky 9 self-check: 8 tasks — if you can finish them alone, you are good

How to use it

Take one Rocky 9 VM (snapshot it first) and work through the 8 tasks in order. Every task has verification commands: if all pass, you can handle this class of problem on your own; if one fails, follow the link back to its page.

The checklist only covers hands-on pages published on this site. The tasks do not come from any official exam bank and do not represent Red Hat certification content.

Task 1: undo a mistaken install

sudo dnf -y install tree
dnf history list | head -3          # note the install transaction ID
sudo dnf -y history undo <ID>
rpm -q tree                          # expected: package tree is not installed

See: dnf transaction rollback

Task 2: open exactly one port

sudo firewall-cmd --permanent --zone=public --add-port=8443/tcp
sudo firewall-cmd --reload
firewall-cmd --zone=public --list-ports        # should include 8443/tcp
sudo systemctl restart firewalld
firewall-cmd --zone=public --list-ports        # still there after restart

See: firewall-cmd port rules

Task 3: install a package offline

# connected host
sudo dnf -y install --downloadonly --destdir=/srv/offline tree
sudo createrepo_c /srv/offline
# isolated host (local.repo points at file:///srv/offline)
sudo dnf --disablerepo="*" --enablerepo=local-offline -y install tree
rpm -q tree

See: Offline package installs

Task 4: the 7 post-install checks

dnf repolist --enabled            # baseos/appstream/extras, CRB off
timedatectl status | grep "Time zone"
hostname -f
getenforce                         # Enforcing
firewall-cmd --zone=public --list-services
needs-restarting -r; echo $?       # 0
rpm -q firewalld chrony

See: First-hour checks

Task 5: rotate an application log

sudo tee /etc/logrotate.d/lab >/dev/null <<'EOF'
/var/log/lab/*.log { daily rotate 3 compress copytruncate }
EOF
sudo logrotate -f /etc/logrotate.d/lab
ls /var/log/lab/                   # expected: a.log (0 bytes) + a.log.1.gz

See: logrotate in practice

Task 6: add 4 GB of swap

sudo fallocate -l 4G /swapfile
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile
swapon --show                      # expected: a /swapfile entry

See: swap sizing

Task 7: pin the package source

sudo dnf --disablerepo="*" --enablerepo=multi install -y tree
rpm -q tree
# add includepkgs=tree to multi.repo, run dnf clean all, then:
dnf --disablerepo="*" --enablerepo=multi list available | grep -c wget   # expected 0

See: Repository conflicts

Task 8: switch DHCP to a static IP

nmcli connection modify "<connection>" ipv4.method manual \
  ipv4.addresses 192.0.2.10/24 ipv4.gateway 192.0.2.1 ipv4.dns 192.0.2.53
nmcli connection up "<connection>"
ip -4 addr show; ip route show default; cat /etc/resolv.conf

See: nmcli static IP

Scoring

Passed	Meaning
8/8	You can handle package management, firewall, networking and storage buffering on your own
6–7	Revisit the failed pages, focusing on the verification commands rather than typing them once
< 6	Redo the tasks in order; write your own verification commands before running anything

Next steps

• Start here: First-hour checks
• Debugging method: /en/troubleshooting/performance/
• Security baseline: Security baseline