1z0-106 Questions and Answers

Understanding the Command:

$ podman run --name=oracleshell -it oraclelinux:8-slim

(Note: The image is likely oraclelinux:8-slim without a space.)

podman run:Creates and starts a new container.

--name=oracleshell:Assigns the name oracleshell to the container.

-it:Runs the container in interactive mode with a pseudo-TTY.

oraclelinux:8-slim:Specifies the image to use.

Option A: The container creates and starts an interactive shell.

Explanation:

The -it option runs the container interactively.

If no command is specified, it executes the default command in the image (usually /bin/bash).

This provides an interactive shell inside the container.

Oracle Linux Reference:

Oracle® Linux 8: Managing Containers-Running Containers Interactively:

"You can run a container in interactive mode using the -i and -t options together."

Option D: The container is created and started in a single command.

Explanation:

The podman run command handles both creation and starting of the container.

There's no need to create the container separately.

Oracle Linux Reference:

Oracle® Linux 8: Managing Containers-Creating and Running Containers:

"The podman run command creates and starts a container in one operation."

Why Other Options Are Incorrect:

Option B:The container does not need to pre-exist; podman run creates it if it doesn't exist.

Option C:If the image doesn't exist locally, podman will attempt to pull it from the registry.

Oracle Linux Reference:

Oracle® Linux 8: Managing Containers-Pulling Images:

"If you attempt to run a container with an image that does not exist locally, Podman automatically pulls the image from a registry."

Option E:The container is not removed upon exit unless the --rm option is used.

Oracle Linux Reference:

Oracle® Linux 8: Managing Containers-Automatically Removing Containers:

"Use the --rm option to automatically remove the container when it exits."

Conclusion:

Correct Options:A, D

Summary:The command creates and starts a new container named oracleshell and opens an interactive shell session inside it.

Option A: Ksplice can be used without a network connection

Explanation:

Ksplice provides anOffline Clientspecifically designed for systems that do not have a direct connection to the internet. This client allows administrators to download Ksplice updates on a system with internet access and then transfer them to the offline system for installation.

This means Ksplice can be effectively used in environments with strict security policies where network connectivity is restricted or not available.

Oracle Linux Reference:

Oracle® Linux 8: Ksplice User's Guide- Section on "Using the Ksplice Offline Client":

"The Ksplice Offline client enables you to apply Ksplice updates to systems that do not have direct access to the Internet or to the Oracle Uptrack server."

Option B: It can patch the kernel without shutting down the system.

Explanation:

The primary purpose of Ksplice is to allow administrators to apply critical security patches to the running kernelwithout requiring a rebootor shutting down the system. This ensures high availability and minimizes downtime, which is crucial for production environments.

Ksplice works by performingjust-in-time (JIT) compilationof kernel patches and applying them directly to the running kernel in memory.

Oracle Linux Reference:

Oracle® Linux 8: Ksplice User's Guide- Introduction:

"Ksplice enables you to keep your systems up to date and secure by applying important kernel security updates without rebooting."

Why Other Options Are Not Correct:

Option C:Yum cannot upgrade a kernel patched by Ksplice

Explanation:

This statement is false. While Ksplice patches the running kernel in memory, yum can still upgrade the kernel packages on disk. After a yum kernel update, a reboot would be necessary to run the new kernel version, but yum operations are not hindered by Ksplice patches.

Oracle Linux Reference:

Oracle® Linux 8: Ksplice User's Guide- Compatibility with Package Managers:

"Ksplice works seamlessly with package management tools like yum and dnf. You can continue to use these tools to manage your kernel packages."

Option D:Ksplice has two clients; each can run in three different modes.

Explanation:

While Ksplice does have two clients (the online and offline clients), the statement about each running in three different modes is inaccurate or misleading. The clients do not operate in "three different modes" per se.

Oracle Linux Reference:

No official documentation supports the claim of "three different modes" for each client.

Option E:The Ksplice client is freely available to all customers.

Explanation:

Ksplice is a feature available to customers with an active Oracle Linux Premier Support subscription. It is not freely available to all users.

Oracle Linux Reference:

Oracle® Linux 8: Ksplice User's Guide- Access Requirements:

"To use Ksplice, your system must be covered by an Oracle Linux Premier Support subscription."

Conclusion:

Options A and B are correct because Ksplice can be used without a network connection via the offline client, and it allows patching the kernel without shutting down the system, ensuring minimal downtime.

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.

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

Understanding the anacrontab Entries:

The /etc/anacrontab file contains the following variables and job definitions:

SHELL=/bin/sh

PATH=/sbin:/bin:/usr/sbin:/usr/bin

MAILTO=root

# the maximal random delay added to the base delay of the jobs

RANDOM_DELAY=45

# the jobs are started during the following hours only

START_HOURS_RANGE=3-22

# period in days delay in minutes job-identifier command

1 5 dailyjob nice run-parts /etc/cron.daily

7 25 weeklyjob nice run-parts /etc/cron.weekly

@monthly 45 monthlyjob nice run-parts /etc/cron.monthly

Variables Explained:

RANDOM_DELAY=45

Specifies that arandom delaybetween 0 and 45 minutes is added to the base delay of each job.

START_HOURS_RANGE=3-22

Jobs are allowed to start only between03:00 (3 AM)and22:00 (10 PM).

Job Delays Calculated:

First Job (dailyjob):

Base Delay:5 minutes

Random Delay:0 to 45 minutes

Total Delay:5 + (0 to 45) =5 to 50 minutes

Second Job (weeklyjob):

Base Delay:25 minutes

Random Delay:0 to 45 minutes

Total Delay:25 + (0 to 45) =25 to 70 minutes

Third Job (monthlyjob):

Base Delay:45 minutes

Random Delay:0 to 45 minutes

Total Delay:45 + (0 to 45) =45 to 90 minutes

Option B: Jobs defined in this anacrontab file can be executed between 15:00 and 22:00

Explanation:

The START_HOURS_RANGE=3-22 setting allows jobs to start between03:00 and 22:00.

Therefore, it's true that jobscan be executed between 15:00 (3 PM) and 22:00 (10 PM).

This statement is correct because the specified time range falls within the allowed start hours.

Oracle Linux Reference:

Oracle® Linux 8: Scheduling Tasks- Section on "Anacron Configuration Files":

"The START_HOURS_RANGE variable defines the time window during which Anacron jobs can run."

Option C: Scripts run by the third job are delayed between 45 and 90 minutes.

Explanation:

The third job (monthlyjob) has abase delay of 45 minutes.

With a RANDOM_DELAY of up to 45 minutes, thetotal delaybefore execution is between45 and 90 minutes.

Therefore, this statement is accurate.

Oracle Linux Reference:

Oracle® Linux 8: Scheduling Tasks- Section on "Understanding Anacron Job Delays":

"Each job's delay is calculated by adding its defined delay to a random value between 0 and RANDOM_DELAY."

Why Other Options Are Not Correct:

Option A:Scripts run by the first job are delayed between 11 and 45 minutes.

Explanation:

The first job (dailyjob) has a total delay between5 and 50 minutes(5-minute base delay plus up to 45 minutes random delay).

Therefore, the statement specifying11 to 45 minutesis incorrect.

Option D:Jobs defined in this anacrontab file are randomly delayed by up to 51 minutes.

Explanation:

The maximum random delay is set by RANDOM_DELAY=45, so the random delay is up to45 minutes, not 51.

Therefore, this statement is false.

Option E:Scripts run by the second job are delayed between 31 and 70 minutes.

Explanation:

The second job (weeklyjob) has a total delay between25 and 70 minutes(25-minute base delay plus up to 45 minutes random delay).

The statement specifies a delay between31 and 70 minutes, which is incorrect because the minimum delay is 25 minutes.

Conclusion:

Options B and C are correct based on the configuration specified in /etc/anacrontab. They accurately reflect the possible execution times and delays for the jobs defined.

Explanation of Answer C:Thesscommand can be used to display all available internal TCP information, including established connections with detailed TCP metrics, which matches the output in Answer C.

Explanation of Answer D:Thesscommand can display listening ports (TCP in this case) with details like congestion control algorithms (cubic), which aligns with Answer D. The output indicates a listening TCP socket on port 80.

Understanding DNF Modules:

DNF modules in Oracle Linux 8 provide a way to offer different versions of software (packages) to users, allowing them to choose the version that best suits their needs. Modules help in managing multiple versions of software by grouping packages, defining streams, and using profiles for configurations.

Option A: Modules are a group of packages that are installed together along with dependencies.

Explanation:

Modulesare collections of packages that are grouped together to represent an application, language runtime, or any logical set.

When you install a module, you are installing a set of packages along with their dependencies.

This grouping ensures that all necessary components are installed for the software to function correctly.

Oracle Linux Reference:

Oracle® Linux 8: Managing Software-About Modules:

"A module is a group of packages that represents a component, such as an application, a language runtime, or a set of tools."

Option B: Installing a module allows a user to select a specific stream.

Explanation:

Streamsin a module represent different versions of the software.

When installing a module, you can select a specific stream to install the desired version.

This allows users to choose between multiple versions of the same software provided within the module.

Oracle Linux Reference:

Oracle® Linux 8: Managing Software-About Module Streams:

"Each module can have one or more streams, which represent versions of the module content."

Example Command:

# dnf module list nodejs

This command lists available streams for the nodejs module.

Option F: Packages exist in multiple streams, where each stream contains a different version.

Explanation:

Within a module, each stream can contain different versions of the packages.

This means the same package can exist in multiple streams but with different versions in each stream.

This setup allows users to install the version of the software that meets their requirements.

Oracle Linux Reference:

Oracle® Linux 8: Managing Software-About Module Streams:

"Different streams can contain different versions of the software, allowing you to select the version that best suits your needs."

Why Other Options Are Incorrect:

Option C: Profiles are used to provide alternate versions of the same module.

Explanation:

Profilesdefine sets of packages within a module stream for specific use cases or configurations, not alternate versions.

Streams provide alternate versions, whereas profiles provide different package sets within a stream.

Oracle Linux Reference:

Oracle® Linux 8: Managing Software-About Module Profiles:

"A profile is a list of packages that defines a particular use case for a module stream."

Option D: Streams are used to define optional configurations of modules.

Explanation:

Streams define different versions of software, not optional configurations.

Optional configurations are managed through profiles within a stream.

Oracle Linux Reference:

Profiles handle configurations, while streams handle versions.

Option E: Streams cannot declare dependencies on the streams of other modules.

Explanation:

Streams can declare dependencies on specific streams of other modules.

This allows modules to work together with compatible versions.

Oracle Linux Reference:

Oracle® Linux 8: Managing Software-Module Dependencies:

"Modules can declare dependencies on specific streams of other modules."

Option G: Switching an enabled module stream automatically changes installed packages.

Explanation:

Switching streams does not automatically change installed packages.

You must reset the module and install the new stream's packages manually.

Oracle Linux Reference:

Oracle® Linux 8: Managing Software-Switching Module Streams:

"To switch to a different module stream, you must reset the module and then install the packages from the new stream."

Conclusion:

Correct Options:A, B, F

Summary:Modules group packages with dependencies, installing a module allows selecting a specific stream (version), and packages can exist in multiple streams with different versions.

Option A (Correct):A user private group (UPG) ensures that each user has their own unique group created with the same name and ID as the user.

Option E (Correct):The UPG model helps prevent other users from modifying files by default, as newly created files are assigned to the user’s unique group and not to a shared group.

Option B (Incorrect):UPG does not give the capability to create new group users; this is related to group management commands.

Option C (Incorrect):UPG does not providesudocapabilities;sudoconfiguration is managed separately.

Option D (Incorrect):UPGs do not limit reading files to group users by default; it depends on specific file permissions.

Oracle Linux Reference:Refer to:

Oracle® Linux 8: Managing Users and Groups

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.

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.

Option A (Correct):The command creates a Kubernetes Deployment, which ensures the specified number of replicas (pods) are running at all times. The deployment will manage the creation and maintenance of these pods to ensure availability.

Option D (Correct):The deployment configuration specifies that the container running inside the pod exposes port 80 (containerPort: 80).

Option B (Incorrect):The deployment is namednginx-deployment, notnginx.

Option C (Incorrect):The command creates a Deployment object that manages multiple pods; it does not directly create a single pod namednginx.

Option E (Incorrect):The command specifies the nginx image version1.14.2, but it will not fail immediately if the image version is not available. Kubernetes will attempt to pull the image, and the failure will happen during that step if the image does not exist.

Oracle Linux Reference:Refer to:

Kubernetes Documentation on Deployments

kubectl createcommand usage details.

Option B (Correct):Btrfs uses a copy-on-write mechanism for both data and metadata, which ensures that the file system is more resilient to crashes and data corruption.

Option E (Correct):Btrfs supports online resizing, meaning that you can change the size of a mounted Btrfs file system without unmounting it.

Option G (Correct):Btrfs automatically defragments files in the background to maintain performance.

Option A (Incorrect):While Btrfs does support mirroring, it is not strictly block device mirroring in the traditional sense like RAID; it uses a different approach to redundancy.

Option C (Incorrect):Btrfs is not a cluster file system; it is designed for local file systems.

Option D (Incorrect):While Btrfs can store small files efficiently, it is not its primary design goal compared to other file systems optimized specifically for small files.

Option F (Incorrect):Btrfs is a file system with integrated volume management capabilities but is not a general-purpose volume manager like LVM.

Oracle Linux Reference:Refer to:

Oracle® Linux 8: Btrfs File System

man btrfsfor features and management.

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.