XK0-005 Multiple Select — 10 Questions

Question 1

A systems administrator wants to monitor system performance in real time. Which TWO commands can be used to display live updating information about processes, CPU, and memory usage? (Select TWO.)

Accepted Answer

top. The `top` command provides a real-time, dynamically updating view of system processes, CPU usage, and memory usage. It refreshes by default every few seconds, making it a standard tool for live performance monitoring. Similarly, `htop` is an enhanced interactive process viewer that offers a more user-friendly interface with color-coded, real-time updates on CPU, memory, and process information.

Answer

ps aux

Answer

sar -u 1 5

Answer

vmstat 1

Question 2

Which TWO of the following are valid methods to enforce disk quota limits on a Linux filesystem? (Select TWO.)

Accepted Answer

Using 'edquota' to set soft and hard limits for users. Option A is correct because 'edquota' is the standard interactive command used to set soft and hard disk quota limits for users or groups on a Linux filesystem. It opens the user's quota settings in a text editor, allowing precise configuration of block and inode limits. Option E is correct because 'quotaon' is the command that enables quota enforcement on a specified filesystem, activating the quota subsystem after limits have been defined.

Answer

Using 'setquota' to set limits in a script

Answer

Running 'repquota' to generate reports

Answer

Running 'quotacheck' to update quota files

Question 3

A database server running on Linux is experiencing high load. The administrator runs 'strace -p <pid>' and sees many 'epoll_wait' and 'futex' calls. Which THREE of the following are possible causes of the high load? (Choose THREE.)

Accepted Answer

Disk I/O contention causing processes to wait.. Option A is correct because 'epoll_wait' indicates the process is waiting for I/O events, and 'futex' calls are used for synchronization. Disk I/O contention can cause the database process to block on these system calls, leading to high load as the kernel schedules other tasks while waiting for I/O to complete.

Answer

CPU frequency scaling is set to powersave.

Answer

A memory leak in the database process.

Question 4

A Linux engineer is troubleshooting a server that fails to boot. The server displays a message indicating 'Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)'. Which TWO actions should the engineer take to resolve this issue? (Choose TWO.)

Accepted Answer

Boot from a rescue disk and rebuild the initramfs with the necessary filesystem modules. The error 'Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)' indicates the kernel cannot locate or mount the root filesystem. Option B is correct because rebuilding the initramfs from a rescue disk ensures the necessary filesystem drivers (e.g., ext4, xfs) are included, which may have been missing or corrupted. Option D is correct because the root= parameter in the bootloader configuration (e.g., GRUB) tells the kernel which device/partition to mount as root; a typo or incorrect value (e.g., wrong UUID or device name) will cause this exact panic.

Answer

Reinstall GRUB to the Master Boot Record

Answer

Run fsck on the root partition to check for filesystem corruption

Answer

Disable SELinux by adding selinux=0 to the kernel command line

Question 5

A Linux system is experiencing kernel panics after a recent update. The administrator wants to boot into a previous kernel version to restore functionality. Which three steps are required to achieve this? (Select THREE).

Accepted Answer

After booting, edit /etc/default/grub and set GRUB_DEFAULT to the saved entry, then run update-grub. Option A is correct because after booting into a working kernel, editing /etc/default/grub to set GRUB_DEFAULT to 'saved' and running update-grub (or grub-mkconfig) ensures that the GRUB bootloader will remember and default to the last successfully booted kernel, which can be the previous version. This step is necessary to make the temporary fix persistent across reboots.

Answer

Run 'yum reinstall kernel' to revert to the previous version

Answer

Edit /etc/fstab to change root filesystem parameters

Question 6

A technician is configuring a system to automatically mount an NFS share at boot. Which two files must be edited or created? (Choose two.)

Accepted Answer

/etc/nfsmount.conf. Option D is correct because `/etc/nfsmount.conf` is the NFS configuration file that can be used to set default mount options for NFS shares, such as protocol version, read/write size, and timeouts. Option E is correct because `/etc/fstab` is the standard file system table that defines how block devices, remote filesystems, and swap partitions are mounted at boot, including NFS shares with the `nfs` or `nfs4` filesystem type.

Answer

/etc/auto.master

Answer

/etc/exports

Answer

/etc/nfs.conf

Question 7

A Linux administrator is hardening a server. Which TWO actions are effective in preventing unauthorized access via SSH? (Select TWO.)

Accepted Answer

Set PermitRootLogin no in /etc/ssh/sshd_config. Option D is correct because setting `PermitRootLogin no` in `/etc/ssh/sshd_config` prevents direct root login via SSH, forcing administrators to log in as a regular user and then use `su` or `sudo` for privilege escalation. This reduces the attack surface by eliminating the ability to brute-force the root password directly over SSH.

Answer

Set PermitRootLogin yes

Answer

Set PasswordAuthentication yes

Answer

Disable the SSH service

Question 8

A security audit identified that the /tmp directory is world-writable. Which THREE steps should be taken to secure /tmp on a Linux system? (Select THREE.)

Accepted Answer

Set the sticky bit on /tmp. Option A is correct because setting the sticky bit on /tmp prevents users from deleting or renaming files owned by other users, even though the directory is world-writable. This is a standard security hardening measure for shared temporary directories.

Answer

Remove world-writable permission from /tmp

Answer

Mount /tmp with the exec option

Question 9

Which THREE of the following are valid methods to troubleshoot a service that fails to start?

Accepted Answer

Run the service executable manually from the command line to see error output.. Option A is correct because running the service executable manually from the command line often reveals stderr output, error codes, or missing configuration details that are suppressed when the service is started by systemd. This direct execution bypasses the service manager's logging and can show immediate, unfiltered error messages that help pinpoint the failure reason.

Answer

Run df -h to check disk space.

Answer

Reload the systemd daemon with systemctl daemon-reload.

Question 10

Which TWO statements are true regarding the use of Ansible for automation? (Choose TWO.)

Accepted Answer

Ansible playbooks are written in YAML.. Option B is correct because Ansible playbooks are written in YAML (YAML Ain't Markup Language), which is a human-readable data serialization standard. YAML allows for simple, declarative syntax to define automation tasks, variables, and handlers, making playbooks easy to write and maintain without requiring programming expertise.

Answer

Ansible requires a dedicated master server to manage nodes.

Answer

Ansible uses a pull-based model where nodes fetch configurations from a central server.

Answer

Ansible modules are written in Ruby.