A Linux administrator is scheduling a system job that runs a script to check available disk space every hour. The Linux administrator does not want users to be able to start the job. Given the following: The Linux administrator attempts to start the timer service but receives the following error message: Which of the following is MOST likely the reason the timer will not start?
Correct Answer: C
Explanation The most likely reason the timer will not start is that the checkdiskspace.timer should be configured to allow manual starts. By default, systemd timers do not allow manual activation via systemctl start, unless they have RefuseManualStart=no in their [Unit] section. This option prevents users from accidentally starting timers that are meant to be controlled by other mechanisms, such as calendar events or dependencies. To enable manual starts for checkdiskspace.timer, the administrator should add RefuseManualStart=no to its [Unit] section and reload systemd. The other options are not correct reasons for the timer not starting. The checkdiskspace.timer unit does not need to be enabled via systemctl enable, because enabling a timer only makes it start automatically at boot time or after a system reload, but does not affect manual activation. The timers.target does not need to be reloaded to get the new configuration, because reloading a target only affects units that have a dependency on it, but does not affect manual activation. The checkdiskspace.timer does not need to be started using the sudo command, because the administrator is already running systemctl as root, as indicated by the # prompt. References: systemd.timer(5) - Linux manual page; systemctl(1) - Linux manual page
XK0-005 Exam Question 12
Which of the following is a function of a bootloader?
Correct Answer: C
Explanation A function of a bootloader is to help load the different kernels to initiate the OS startup process. A bootloader is a program that runs when the system is powered on and prepares the system for booting the OS. A bootloader can load different kernels, which are the core components of the OS, and pass the control to the selected kernel. A bootloader can also provide a menu for the user to choose which kernel or OS to boot. This is a correct function of a bootloader. The other options are incorrect because they are either functions of the kernel (initialize devices or mount root filesystem) or functions of the init system (trigger the start of system services). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 8: Managing the Linux Boot Process, page 265.
XK0-005 Exam Question 13
Rugged appliances are small appliances with ruggedized hardware and like Quantum Spark appliance they use which operating system?
Correct Answer: B
Explanation Rugged appliances are small appliances with ruggedized hardware that use Gaia embedded as their operating system. Gaia embedded is a version of Gaia that is optimized for embedded devices such as Rugged appliances and Quantum Spark appliances. Gaia embedded supports features such as VPN, firewall, identity awareness, application control, URL filtering, and anti-bot. Gaia embedded does not use Centos Linux, Gaia, or Red Hat Enterprise Linux version 5 as their operating system. References: Check Point Rugged Appliance Datasheet, page 1.
XK0-005 Exam Question 14
A systems administrator received a notification that a system is performing slowly. When running the top command, the systems administrator can see the following values: Which of the following commands will the administrator most likely run NEXT?
Correct Answer: A
Explanation The command vmstat will most likely be run next by the administrator to troubleshoot the system performance. The vmstat command is a tool for reporting virtual memory statistics on Linux systems. The command shows information about processes, memory, paging, block IO, interrupts, and CPU activity. The command can help the administrator identify the source of the performance issue, such as high CPU usage, low free memory, excessive swapping, or disk IO bottlenecks. The command can also be used with an interval and a count to display the statistics repeatedly over time and observe the changes. The command vmstat will provide useful information for diagnosing the system performance and finding the root cause of the issue. This is the most likely command to run next after the top command. The other options are incorrect because they either do not show the virtual memory statistics (strace or lsof) or do not provide more information than the top command (htop). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 14: Managing Processes and Scheduling Tasks, page 425.
XK0-005 Exam Question 15
A systems administrator configured firewall rules using firewalld. However, after the system is rebooted, the firewall rules are not present: The systems administrator makes additional checks: Which of the following is the reason the firewall rules are not active?
Correct Answer: D
Explanation The reason the firewall rules are not active is that the firewalld service is not enabled. This means that the service will not start automatically at boot time or after a system reload. To enable the firewalld service, the systems administrator needs to use the command sudo systemctl enable firewalld. This will create a symbolic link from the firewalld service file to the appropriate systemd target, such as multi-user.target. Enabling the service does not start it immediately, so the systems administrator also needs to use the command sudo systemctl start firewalld or sudo systemctl reload firewalld to activate the firewall rules. The other options are not correct reasons for the firewall rules not being active. iptables is not conflicting with firewalld, because firewalld uses iptables as its backend by default. The wrong system target is not activated, because firewalld is independent of the system target and can be enabled for any target. FIREWALL_ARGS has no value assigned, but this is not a problem, because FIREWALL_ARGS is an optional environment variable that can be used to pass additional arguments to the firewalld daemon, such as --debug or --nofork. If FIREWALL_ARGS is empty or not defined, firewalld will use its default arguments. References: firewalld.service(8) - Linux manual page; firewall-cmd(1) - Linux manual page; systemctl(1) - Linux manual page
