Hard — XK0-006 Practice Quiz

Question 1

An Ansible playbook installs several packages using a loop and registers the output. A teammate wants a subsequent task to print the name of each package that was actually installed (changed), skipping packages that were already present. Which construct correctly iterates over the registered results to access per-item status?

Accepted Answer

Loop over the registered variable's '.results' list and reference each element's '.changed' and '.item' attributes

Answer

Reference the registered variable's top-level '.changed' attribute inside a single debug task

Answer

Use 'with_items' on the original package list and reference 'ansible_facts.packages' for status

Answer

Loop over the registered variable directly, since a looped task stores each result as a top-level key

Question 2

After a kernel update, a RHEL 9 server fails to boot. The console displays a kernel panic with the message: 'VFS: Unable to mount root fs on unknown-block(0,0)'. You boot into the previous working kernel entry from the GRUB menu, and the system starts normally. Comparing /boot, you notice the initramfs file for the new kernel is 0 bytes. What is the most appropriate action to fix booting into the new kernel?

Accepted Answer

Reinstall the kernel package and regenerate the initramfs with 'dracut -f --kver <new-kernel-version>', then update GRUB

Answer

Run 'dracut --force /boot/initramfs-$(uname -r).img $(uname -r)' after booting the new kernel version to regenerate the initramfs

Answer

Edit /etc/fstab to change the root filesystem entry to use the device path instead of the UUID

Answer

Run 'grub2-mkconfig -o /boot/grub2/grub.cfg' to rebuild the boot menu and point it at the working kernel

Question 3

A monitoring alert reports that a database server has a load average of 24.0 on an 8-core system, yet top shows CPU usage is only about 15% with over 80% idle. Users report the application feels extremely sluggish. What is the MOST likely cause of the high load average?

Accepted Answer

Numerous processes are stuck in uninterruptible sleep (D state) waiting on blocked I/O

Answer

A single runaway process is consuming all available CPU cycles

Answer

The system is swapping heavily and CPU is spending time in the OOM killer

Answer

The load average calculation is inaccurate and should be ignored on multi-core systems

Question 4

Users on a Linux workstation report that opening internal web applications by hostname takes 5-10 seconds before loading, while accessing the same sites by IP address is instant. Running 'dig +short intranet.corp.local' against the configured DNS server returns the correct record in under 20 ms. Which action is MOST likely to resolve the delay?

Accepted Answer

Reorder the 'hosts:' line in /etc/nsswitch.conf and reduce lookup timeouts, ensuring the resolver does not attempt an unreachable source (such as mDNS/'mdns4') before falling through to DNS

Answer

Flush the ARP cache with 'ip neigh flush all' to force fresh MAC address resolution

Answer

Increase the MTU on the primary interface to 9000 to speed up large HTTP transfers

Answer

Restart the DNS server daemon because its zone file is returning stale records

Question 5

A server has an ext4 filesystem on the logical volume /dev/vg0/data currently mounted at /data. You need to shrink this logical volume from 200 GB to 120 GB to free space in the volume group for another LV. The filesystem currently uses about 80 GB. Which sequence correctly and safely reduces the logical volume without data loss?

Accepted Answer

Unmount /data, run e2fsck -f on the device, resize2fs to 120G, then lvreduce -L 120G on the LV

Answer

Run resize2fs online while /data is mounted, then lvreduce -L 120G on the LV

Answer

Run lvreduce -L 120G first, then resize2fs to grow the filesystem back to the new size

Answer

Unmount /data, run xfs_growfs to 120G, then lvreduce -L 120G on the LV

Question 6

A Linux administrator manages a fleet of servers joined to a central LDAP directory using SSSD. Users authenticate correctly, but members of the LDAP group 'dbadmins' report they cannot run privileged commands with sudo, even though a rule exists in /etc/sudoers referencing '%dbadmins'. Running 'id' as one of these users shows their LDAP username but does NOT list the 'dbadmins' group. What is the MOST likely cause?

Accepted Answer

SSSD is not resolving the user's LDAP group memberships, so the group does not appear in the user's ID and the sudoers rule never matches

Answer

The 'sudo' package is not installed on the affected servers

Answer

The sudoers rule must reference the group by GID number rather than by name for LDAP groups

Answer

Password authentication must be disabled in sshd_config before sudo group rules take effect