Oracle 1z0-106 Oracle Linux 8 Advanced System Administration Exam Practice Test

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 A:When thechrootcommand is executed with/jail, the environment is changed to use/jailas its new root directory. Inside this environment, only the directories and files copied into/jailare accessible. Since/jaildoes not contain a/rootdirectory, the commandcd(which defaults to changing to the user's home directory) will fail, displayingNo such file or directory. Thepwdcommand shows the root of the chroot environment (/), andlsdisplays the contents of/jail, which includesbinandlib64.

Option A (Correct):In rsyslog, afilteris used to determine which messages should be selected for further processing. Filters can be based on different criteria such as facility, severity, or specific message content.

Option B (Correct):Anactionin rsyslog defines what to do with messages that match a filter. Actions can include writing to a log file, sending to a remote server, running a script, etc.

Option C (Incorrect):A parser is not typically a component for creating a new rsyslog rule; it is involved in interpreting message formats.

Option D (Incorrect):A module in rsyslog is a loadable component that provides additional capabilities, such as support for different protocols or output formats. It is not a direct component of a logging rule.

Option E (Incorrect):Security policy is unrelated to the basic components used for defining rsyslog rules.

Oracle Linux Reference:Refer to:

Oracle® Linux 8: Configuring Rsyslog

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.

Explanation of Answer A:Oracle Linux 8 uses cgroups version 2 (cgroups v2) by default. cgroups v2 is a unified hierarchy system that introduces improvements over version 1, including a simplified interface and better resource management capabilities.

Explanation of Answer B:A control group (cgroup) is a mechanism for grouping processes and setting limits or parameters on their resource usage, such as CPU, memory, or I/O. These limits and parameters are configured and managed through the cgroups filesystem.

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

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.

The/etc/sysconfigdirectory contains configuration files for various system services and applications. The content of this directory depends on which packages are installed on the system. Each package may provide one or more configuration files stored in/etc/sysconfigto control its behavior.

Option A (Correct):The/procfile system is a pseudo-file system that contains runtime system information (e.g., system memory, mounted devices, hardware configuration, etc.). Files such as/proc/meminfoand/proc/cpuinfoprovide detailed information about memory and CPUs, respectively.

Option C (Correct):The/sysfile system, also known as sysfs, provides a view of the kernel's device model. It contains information about system hardware, including CPUs and memory. For example,/sys/devices/system/cpu/contains directories and files that provide detailed information about each CPU.

Option B (Incorrect):The/sysfile system does not contain a list of running processes. Running processes are listed in the/procfile system, with each process having its own directory under/proc.

Option D (Incorrect):/procdoes not contain a list of network drivers specifically. Network driver information is available under/proc/net, but this does not equate to a list of drivers.

Option E (Incorrect):The/sysfile system does not contain a list of mounted devices. Mounted devices are listed in/proc/mountsor the/etc/mtabfile.

Oracle Linux Reference:For more details, see:

Oracle® Linux 8: The/procand/sysFile Systems.

Option C (Correct):This command sequence first loads the 802.1q module needed for VLAN tagging, then creates a VLAN interface (eth0.800) on the base interface (eth0), assigns an IP address (10.135.1.120/24), and sets the VLAN interface up.

Option A, B, D (Incorrect):These options have syntactical errors or missing parameters that make them incorrect for setting up a fully functional and accessible VLAN interface.

Oracle Linux Reference:Refer to:

Oracle® Linux 8: Configuring VLANs

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 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 C (Correct):If a device named/dev/hdbwith theide-diskdriver is discovered, a symbolic link/dev/sparediskwill be created, pointing to/dev/hdb.

Option D (Correct):TheKERNEL=="hdb"match specifies that the device will have the kernel device name/dev/hdb.

Option A (Incorrect):This is incorrect because existing symbolic links are not overwritten unless explicitly defined.

Option B (Incorrect):The device itself is not renamed to/dev/sparedisk; rather, a symbolic link is created.

Option E (Incorrect):The rule specifically requires bothKERNEL=="hdb"andDRIVER=="ide-disk"to match; it is not an either/or condition.

Understanding the Automounter Configuration:

/etc/auto.master:

/net -hosts

/- auto.direct ro

The /- auto.direct ro line indicates:

Mount Point Prefix:/ (direct mounts)

Map File:auto.direct

Global Mount Options:ro (read-only)

/etc/auto.direct:

/nfs1 host01:/export/share1

/nfs2 -sync host01:/export/share2

/nfs3 host02:/export/share3

/nfs1 and /nfs3:

No specific mount options in auto.direct.

Inherit the ro option from /etc/auto.master.

/nfs2:

Specifies -sync option in auto.direct.

Inherits ro from /etc/auto.master.

Mount options are ro,sync.

Mount Options Resolution:

Global Options (ro) apply to all entries unless overridden.

Per-Entry Options in auto.direct override or supplement global options.

Effective Mount Options:

/nfs1:

ro (from /etc/auto.master)

Default NFS options (async unless sync is specified)

/nfs2:

ro (from /etc/auto.master)

sync (specified in auto.direct)

/nfs3:

ro (from /etc/auto.master)

Default NFS options (async)

Oracle Linux Reference:

Oracle® Linux 8: Configuring File Systems-Automounter Configuration:

"Options specified in the master map apply to all entries in the map unless overridden by entries in the map itself."

NFS Default Options:

"By default, NFS mounts are asynchronous (async) unless the sync option is specified."

Conclusion:

/nfs1 and /nfs3:Mounted with ro,async.

/nfs2:Mounted with ro,sync.

Correct Option:A

Understanding logrotate:

The logrotate utility manages log files by rotating, compressing, and removing them based on configuration.

It helps prevent log files from consuming excessive disk space.

Option A: Rotating Log Files as Specified

Explanation:

logrotate rotates logs according to the specified criteria (size, time interval).

Rotation involves renaming the current log file and starting a new one.

Oracle Linux Reference:

Oracle® Linux 8: Managing Log Files-Using logrotate:

"The logrotate utility simplifies the administration of log files by automatically rotating, compressing, and removing log files."

Option C: Compressing Log Files

Explanation:

logrotate can compress old log files after rotation to save disk space.

Compression is typically done using gzip.

Oracle Linux Reference:

Oracle® Linux 8: Managing Log Files-Configuring logrotate:

"You can configure logrotate to compress rotated log files by using the compress option."

Explanation of Answer E:This option correctly matches the Kubernetes components with their descriptions:

Kubectl- d. Command-line interface used to control Kubernetes

Etcd- f. Stores configuration data relating to the cluster

Kubelet- c. Agent that allows nodes to communicate with the API

Kube-proxy- e. Performs networking functions and routes network traffic

Kube-apiserver- a. Processes and validates requests and performs operations

Kube-scheduler- b. Determines where containers should run based on resource availability

Explanation of Answer A:Consistent network device naming is enabled by default in Oracle Linux 8. This feature ensures that network interfaces retain their names across reboots, which is important for maintaining network configuration consistency. This is managed through the Predictable Network Interface Names feature, which is part of thesystemdproject and is implemented inudev.

Explanation of Answer B:Theudevdevice manager is responsible for dynamically managing device nodes in the/devdirectory. It generates network interface names based on several naming schemes, such as the interface’s physical location on the bus (likeenp0s3), MAC address, or other attributes. These schemes are used to provide consistent and predictable names for network interfaces.