EX200 Red Hat Certified System Administrator - RHCSARHEL 10 Question and Answers

Solution:

Create the script:

mkdir -p /usr/local/bin

cat > /usr/local/bin/backup-now.sh < < 'EOF'

#!/bin/bash

tar -czf /root/etc-$(date +%F).tar.gz /etc

EOF

chmod +x /usr/local/bin/backup-now.sh

Create the unit file:

cat > /etc/systemd/system/backup-now.service < < 'EOF'

[Unit]

Description=Run manual etc backup

[Service]

Type=oneshot

ExecStart=/usr/local/bin/backup-now.sh

[Install]

WantedBy=multi-user.target

EOF

Reload and test:

systemctl daemon-reload

systemctl start backup-now.service

systemctl status backup-now.service

Detailed Explanation:

Type=oneshot is correct for a task that runs and exits.

ExecStart points to the script.

systemctl daemon-reload is required after adding a new unit file.

RHEL 10 systemd documentation covers manual unit creation and management. ( Red Hat Documentation )

Solution:

Set the hostname:

hostnamectl set-hostname server1.example.com

Configure the existing connection with a static IP:

nmcli connection modify ens160 ipv4.address 192.168.1.2/24 ipv4.gateway 192.168.1.1 ipv4.dns 1.1.1.1 ipv4.method manual connection.autoconnect yes

Bring the connection up:

nmcli connection up ens160

Detailed Explanation:

hostnamectl is the correct modern command for changing the system hostname.

nmcli is the correct tool for RHEL 10 network configuration because the old ifcfg style is removed in RHEL 10, and NetworkManager keyfiles are the supported model.

ipv4.method manual tells NetworkManager to use static addressing.

connection.autoconnect yes ensures the profile activates automatically after reboot.

nmcli connection up ens160 applies the changes immediately.

Solution:

firewall-cmd --permanent --add-service=http

firewall-cmd --reload

firewall-cmd --list-services

Detailed Explanation:

--permanent saves the rule.

--reload applies it.

--list-services verifies the active configuration.

Firewalld remains the standard firewall interface in RHEL 10. ( Red Hat Documentation )

Solution:

sed -i '/^pool /d;/^server /d' /etc/chrony.conf

echo "server time.example.com iburst" > > /etc/chrony.conf

systemctl enable --now chronyd

systemctl restart chronyd

chronyc sources -v

chronyc tracking

Detailed Explanation:

chronyd is the RHEL 10 NTP implementation.

iburst speeds up initial synchronization.

chronyc sources -v and chronyc tracking confirm the sync state.

Red Hat’s RHEL 10 time synchronization documentation uses chrony as the supported NTP implementation. ( Red Hat Documentation )

Solution:

Reboot the system.

Interrupt GRUB boot.

Press e to edit the boot entry.

On the linux line, append:

rd.break

Boot with Ctrl+x.

At the emergency shell:

mount -o remount,rw /sysroot

chroot /sysroot

passwd root

touch /.autorelabel

exit

exit

Detailed Explanation:

rd.break drops you into an early emergency environment.

/sysroot contains the real root filesystem.

mount -o remount,rw /sysroot makes it writable.

chroot /sysroot changes into the installed system.

passwd root resets the password.

touch /.autorelabel is critical so SELinux relabels files on next boot.

Solution:

Create the destination directory if needed:

mkdir -p /root/tomfiles

Find and copy:

find / -type f -user tom -exec cp -pvf {} /root/tomfiles/ \;

Detailed Explanation:

find / searches the whole filesystem.

-type f restricts results to files.

-user tom matches owner tom.

-exec cp -pvf copies each file with verbose and force options.

mkdir -p is added as a safe preparation step.

Solution:

Create the Quadlet file:

mkdir -p /etc/containers/systemd

cat > /etc/containers/systemd/sleepy.container < < 'EOF'

[Container]

Image=registry.access.redhat.com/ubi10/ubi

ContainerName=sleepy

Exec=sleep 3600

[Install]

WantedBy=multi-user.target

EOF

Reload and enable:

systemctl daemon-reload

systemctl enable --now sleepy.service

systemctl status sleepy.service

Detailed Explanation:

Quadlet is the preferred modern way to manage Podman containers with systemd for new configurations.

The .container file is translated into a systemd-managed service.

RHEL 10 documentation notes that podman generate systemd still exists, but Quadlets are preferred for new setups. ( Red Hat Documentation )

Solution:

mkdir -p /share/projects

chown alex /share/projects/

chmod a+rwx,+t /share/projects/

ls -ld /share/projects/

Detailed Explanation:

chmod a+rwx gives read, write, and execute to everyone.

+t sets the sticky bit.

Sticky bit on a shared directory means users can create files, but only the file owner, directory owner, or root can delete them.

This is the same model used on /tmp.

Solution:

dnf install -y dnf-automatic

systemctl enable --now dnf-automatic.timer

systemctl list-timers --all | grep dnf

Detailed Explanation:

dnf-automatic provides automated update checking and installation features.

The timer unit schedules the checks.

RHEL 10 DNF documentation specifically documents the dnf-automatic timer units. ( Red Hat Documentation )