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

Solution:

groupadd ops

useradd sara

usermod -aG ops sara

id sara

Detailed Explanation:

groupadd creates the group.

useradd creates the user.

usermod -aG adds the user to a supplementary group without removing existing memberships.

id sara confirms the result.

Solution:

lvcreate -L 1G -n lvbackup vgdata

mkfs.xfs /dev/vgdata/lvbackup

mkdir -p /backup

echo "/dev/vgdata/lvbackup /backup xfs defaults 0 0" > > /etc/fstab

mount -a

df -h /backup

Detailed Explanation:

lvcreate allocates a new LV from the existing VG.

mkfs.xfs creates the filesystem.

/etc/fstab makes the mount persistent across reboot.

mount -a tests the fstab entry immediately.

RHEL 10 storage documentation continues to use LVM and XFS as core administration topics. ( 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:

Reboot the server.

At the GRUB menu, highlight the kernel entry and press e.

Find the line starting with linux.

Append:

systemd.unit=emergency.target

Press Ctrl+x to boot.

Detailed Explanation:

This changes the boot target only for the current boot.

Emergency mode is useful for rescue and maintenance tasks.

Red Hat’s RHEL 10 systemd guidance documents booting with systemd.unit= < name > .target from GRUB. ( Red Hat Documentation )

Solution:

mkdir -p /root/d1

find /usr/local -type f -size +3k -size -5k -exec cp -rvf {} /root/d1/ \;

chmod g+s /root/d1

ls -ld /root/d1

Detailed Explanation:

-size +3k means greater than 3 KB.

-size -5k means less than 5 KB.

chmod g+s sets the SGID bit on the directory.

SGID on a directory causes new files created there to inherit the directory’s group.

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:

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:

Read-only access:

setfacl -m u:john:r-- /share/dev

Read-write access:

setfacl -m u:john:rw- /share/dev

Remove ACL permissions:

setfacl -m u:john:--- /share/dev

Detailed Explanation:

setfacl -m modifies the ACL.

u:john:r-- grants read only.

u:john:rw- grants read and write.

u:john:--- effectively removes access for that ACL entry.

ACLs are used when standard owner/group/other permissions are not enough.

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.