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

Solution:

Open the firewall port and HTTP service:

firewall-cmd --permanent --add-port=82/tcp

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

firewall-cmd --reload

Add SELinux port labeling:

semanage port -a -t http_port_t -p tcp 82

Detailed Explanation:

firewall-cmd --permanent makes the change persistent.

--add-port=82/tcp opens the custom TCP port.

--add-service=http keeps standard HTTP allowed too.

SELinux blocks services on unexpected ports unless the port is labeled correctly.

http_port_t tells SELinux that port 82 is valid for web services.

Solution:

lvextend -L +500M /dev/vgdata/lvbackup

xfs_growfs /backup

df -h /backup

Detailed Explanation:

lvextend increases the LV size.

xfs_growfs expands the XFS filesystem while mounted.

This is a classic RHCSA storage task and aligns with RHEL 10 LVM/XFS workflows. ( Red Hat Documentation )

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 )

Solution:

dnf install -y vdo kmod-kvdo lvm2

pvcreate /dev/sdc

vgcreate vdo-volumegroup /dev/sdc

lvcreate --type vdo -n vdo-logicalvolume -L 5G -V 50G vdo-volumegroup/vdo-pool

mkfs.xfs /dev/vdo-volumegroup/vdo-logicalvolume

Detailed Explanation:

VDO provides compression and deduplication.

-L 5G sets the physical backing size.

-V 50G sets the logical exposed size.

This allows thin, optimized storage presentation.

The exact commands are taken from the RHCSA dataset embedded in the uploaded lab HTML.

Solution:

stratis filesystem snapshot pool1 fs1 fs1-snap

stratis filesystem list

Detailed Explanation:

This creates a snapshot of the existing Stratis file system.

Snapshots are useful for rollback, backup, and testing operations.

Stratis features, including pool and file-system management, are part of RHEL 10 file-system administration. ( Red Hat Documentation )

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:

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:

pvcreate /dev/sdb3

vgcreate -s 16M VG1 /dev/sdb3

lvcreate -l 30 -n LV1 VG1

mkfs.ext4 /dev/VG1/LV1

Detailed Explanation:

vgcreate -s 16M sets PE size to 16 MB.

lvcreate -l 30 allocates 30 extents.

30 × 16 MB = 480 MB total LV size.

mkfs.ext4 creates the filesystem.

Solution:

dd if=/dev/zero of=/swapfile bs=1M count=512

chmod 600 /swapfile

mkswap /swapfile

swapon /swapfile

echo "/swapfile swap swap defaults 0 0" > > /etc/fstab

swapon --show

Detailed Explanation:

dd creates the file.

chmod 600 protects swap contents.

mkswap prepares the file as swap.

swapon activates it now.

/etc/fstab ensures it is enabled at boot.