1z0-106 Exam Dumps - Oracle Linux Administration Questions and Answers

Option A (Correct):/lib64/securityis a common directory where PAM (Pluggable Authentication Module) libraries are stored for 64-bit systems.

Option D (Correct):/lib/securityis another directory where PAM libraries are stored, usually on 32-bit systems or as a fallback for 64-bit systems.

Option B (Incorrect):/etc/pam.dcontains configuration files for PAM modules but does not store the modules themselves.

Option C (Incorrect):/usr/libis a general directory for libraries but does not specifically store PAM modules.

Option E (Incorrect):/var/libis typically used for variable state information and is not relevant for storing PAM modules.

Oracle Linux Reference:Refer to:

Oracle® Linux 8: Managing Authentication

Option D: anacron jobs may run only once a day.

Explanation:

Anacronis designed for systems that are not running continuously (e.g., desktops or laptops that may be powered off at night). It ensures that scheduled tasks are executed at the specified intervals.

Anacron jobs are defined with periods indays. The minimal unit of time for scheduling in Anacron isone day. Therefore, Anacron can schedule jobs to runonce a dayat most.

It is not intended for tasks that need to run multiple times per day.

Oracle Linux Reference:

Oracle® Linux 8: Scheduling Tasks- Section onAnacron Configuration Files:

"Anacron is used to run commands periodically with a frequency specified in days."

Option E: anacron jobs are used to run cron jobs if the system was powered off when they were scheduled to run.

Explanation:

Anacron complements Cron by ensuring thatscheduled jobs are not missedif the system is powered off or in standby mode at the time they were supposed to run.

When the system boots up, Anacron checks for any scheduled jobs that did not run and executes them accordingly.

This is particularly useful for laptops or desktops that are not always on.

Oracle Linux Reference:

Oracle® Linux 8: Scheduling Tasks- Section onUnderstanding Anacron:

"Anacron is designed to run commands periodically with specified frequency, but unlike cron, it does not assume that the system is running continuously."

Why Other Options Are Not Correct:

Option A:cron jobs may run only once a minute.

Explanation:

Cron allows scheduling tasks with a minimum granularity ofone minute. However, this means that tasks can be scheduled to runevery minute, not limited to only once a minute.

Multiple cron jobs can be scheduled to run at the same minute.

Therefore, the statement is misleading; cron jobs can runas frequently as every minute, but notonly once a minute.

Option B:All crontabs are held in the /etc/cron.d directory.

Explanation:

The /etc/cron.d directory is used for system-wide cron jobs provided by packages or administrators.

User-specific cron jobs are stored in /var/spool/cron/ or managed via the crontab command and not placed in /etc/cron.d.

Additionally, the system crontab file is /etc/crontab, and there are also directories like /etc/cron.hourly, /etc/cron.daily, etc.

Option C:The crond daemon looks for jobs only in /etc/crontab.

Explanation:

The crond daemon checks multiple locations for scheduled jobs:

User crontabs managed via the crontab -e command (stored in /var/spool/cron/).

System-wide crontab file (/etc/crontab).

The /etc/cron.d/ directory.

The /etc/cron.hourly/, /etc/cron.daily/, /etc/cron.weekly/, and /etc/cron.monthly/ directories.

Therefore, crond does not look for jobsonlyin /etc/crontab.

Conclusion:

OptionsDandEare correct because they accurately describe the characteristics and purposes of Anacron in the context of scheduling tasks on an Oracle Linux system.

Option B (Correct):Thefdisk -lcommand lists information about all available disks, including their sizes, partition tables, and partition details.

Option E (Correct):fdiskcannot handle disks larger than 2 TB because it is limited to the Master Boot Record (MBR) partitioning scheme. To manage larger disks (over 2 TB), the GUID Partition Table (GPT) is required, andfdiskdoes not fully support GPT.

Option A (Incorrect):fdiskdoes not support HFS (Hierarchical File System, used by macOS). It primarily supports MBR and has limited support for GPT.

Option C (Incorrect):fdiskdoes not support partitioning disks larger than 2 TB with GPT;gdiskorpartedshould be used instead.

Option D (Incorrect):fdiskdoes not divide logical devices into block disks called partitions; it operates on physical storage devices to create partitions.

Oracle Linux Reference:Refer to:

Oracle® Linux 8: Managing Disks and Partitions

man fdiskfor more details on the usage and limitations of thefdiskutility.

Explanation of Answer D:The entrypool pool.ntp.org offlinein the/etc/chrony.conffile specifies that thechronydservice should not automatically poll the NTP pool servers atpool.ntp.orguntil it is explicitly enabled by thechronyccommand. This setting is typically used in environments where the network is not always available (e.g., laptops or isolated systems) to avoid unnecessary polling.

Explanation of Answer B:The commandssh -L 5011:127.0.0.1:80 bob@10.10.2.20 -f sleep 30creates a local port forward. This means port5011on the client machine is forwarded to port80on the remote machine (10.10.2.20) using the SSH connection.

Explanation of Answer E:The-foption of thesshcommand causes the SSH connection process to fork to the background after authentication is complete. Thesleep 30command keeps the SSH connection alive for 30 seconds.

Explanation of Answer C:Bothatandbatchcan accept commands from standard input or from a file specified using the-foption. This allows scheduling of tasks by providing the commands directly or reading them from a file.

Explanation of Answer E:Theatcommand schedules a one-time task to run at a specified time. It is used to execute commands once at a particular time in the future.

To use a file as swap space, it must first be initialized with themkswapcommand. Theddcommand creates an empty file, butmkswapformats this file to be used as swap space. This command writes the necessary swap header to the file, making it recognizable by the system as a valid swap area.

Explanation of Answer D:After initializing the swap file withmkswap, you can optionally assign a label to the swap file using theswaplabelcommand. This is not strictly required, but it can be useful for identifying swap files, especially if you are using multiple swap devices.

The530 Permission deniederror indicates that the user is not allowed to log in. In vsFTPd, if theUSERLIST_ENABLEoption is set toYESin/etc/vsftpd/vsftpd.conf, and theoracleuser is listed in/etc/vsftpd/user_list, that user is explicitly denied access to the FTP server.