sca_sles15 SUSE Certified Administrator in Enterprise Linux 15 Questions and Answers

To add additional physical volumes to an existing volume group, use the vgextend command. The vgextend command increases a volume group's capacity by adding one or more free physical volumes.

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/4/html/cluster_logical_volume_manager/vg_grow#:~:text=To%20add%20additional%20physical%20volumes,or%20more%20free%20phys ical%20volumes.

The command that is used to add new physical volumes to an existing volume group is vgextend. This command will extend a volume group by adding one or more physical volumes to it. The physical volumes must be initialized with pvcreate before they can be added to a volume group. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-lvm-vgs.html#sec-lvm-vgs-add-pv

The valid device types are character and block devices. Character devices are devices that transfer data byte by byte, such as keyboards, mice, terminals, etc. Block devices are devices that transfer data in fixed-size blocks, such as disks, CD-ROMs, etc. Pipe, null, redirect, udev, and network are not device types but rather concepts or components related to devices or device management. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-devices.html

The name of the system logging facility in SUSE Linux Enterprise is syslog-ng. It is a flexible and scalable implementation of the syslog protocol that can handle various types of log messages from different sources and destinations. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/cha-syslog.html

To access updates for SLE, you need an account with SUSE Customer Center and a SLE Product Key. SUSE Customer Center is a web portal that allows you to manage your subscriptions, products, and services from SUSE. A SLE Product Key is a unique code that activates your subscription and entitles you to receive updates and support for your SLE product. You can register your product key with your SUSE Customer Center account and assign it to your system. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/cha-registration.html

For programs to leverage PolKit they are split into two separate processes. The statements below that are true regarding these two PolKit processes are:

• The Mechanism process runs in the System Context.
• The Policy Agent process runs in the User Session.

The Mechanism process is responsible for performing privileged actions on behalf of unprivileged users. It runs as root in the System Context and communicates with PolKit via D-Bus. The Policy Agent process is responsible for requesting authorization from users when they attempt to perform privileged actions. It runs as a normal user in the User Session and communicates with PolKit via D-Bus. References: https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-polkit.html#sec-polkit-processes

Save a File in Vim / Vi #The command to save a file in Vim is :w.

To save the file without exiting the editor, switch back to normal mode by pressing Esc, type :w and hit Enter.

https://linuxize.com/post/how-to-save-file-in-vim-quit-editor/

The w command will save the current file without exiting Vim. It stands for write. The other commands are either invalid or will exit Vim after saving. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/cha-vim.html#sec-vim-save

The option for zypper that will list the available patches is zypper lp. This command will display a table of patches that are applicable to your system but not yet installed. It will show the patch name, category, severity, summary, and status for each patch. You can use zypper patch to install all available patches or zypper patch-info to get more details about a specific patch. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-zypper.html#sec-zypper-patches

The command that is used to ensure an ext3 file system is checked every 50 times it is mounted is tune2fs. The tune2fs command can be used to adjust various parameters of an ext2, ext3, or ext4 file system. The -c option can be used to set the maximum number of mounts between two file system checks. For example, tune2fs -c 50 /dev/sda1 will set the check interval to 50 mounts for /dev/sda1. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-tune2fs.html

The commands that can be used to terminate processes are kill and killall. The kill command can be used to send a signal to a process specified by its process ID (PID). The default signal is SIGTERM, which requests a graceful termination of the process. The killall command can be used to send a signal to one or more processes specified by their name. It will match all processes that belong to the current user unless otherwise specified. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-cli-processes.html#sec-cli-processes-kill

If you have a service named tftp, the command and options that would enable tftp to start automatically when the server starts are systemctl enable tftp. This command will create symbolic links in the appropriate systemd target directories to enable the tftp service unit. To start the service immediately, you can also use systemctl start tftp or systemctl enable --now tftp. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/cha-systemd-services.html#sec-systemd-enable

The term “action” means an action that defines where a log message ends up such as in a regular file or database table when referring to system logging in SUSE Linux Enterprise. An action is part of a rule that specifies how to process a log message based on its properties. An action can be one of the following types: file, pipe, shell, template, discard, stop, call, omusrmsg, ommysql, ompgsql, etc. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/cha-syslog.html#sec-syslog-config-actions

The screen command will allow you to create and manage multiple terminal sessions that can be detached and resumed later. You can use the screen command to start a new session, then detach it with Ctrl-a d, and reattach it from another location with screen -r. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/cha-screen.html

The UID that the root user has is 0. The UID (user ID) is a numeric value that uniquely identifies a user on the system. The root user is the superuser or administrator who has full privileges and access to all files and commands on the system. The root user always has the UID of 0, regardless of its name or password. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-user-group.html#sec-user-group-root

The command that gives you a real-time view of the processes running on your system by giving you a continuously updated list is top. The top command will display various information about system performance and resource usage, such as CPU load, memory usage, swap usage, etc., as well as a list of processes sorted by CPU utilization by default. You can use various keyboard commands to interact with top and change its behavior and output. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-cli-processes.html#sec-cli-processes-top

The openSUSE Leap version of Linux is designed for desktop power users and developers. It is a community-driven distribution that offers a stable and reliable operating system with cutting-edge software and tools. It is suitable for personal use, development, testing, and experimentation. It is not intended for high-availability or data center environments that require enterprise-level support and security. References:https://en.opensuse.org/Portal:Leap

The command that will take a foreground process and suspend it, and then place it in the background as a stopped job is Ctrl+Z. This keyboard shortcut will send a SIGTSTP signal to the foreground process group, which will stop its execution and return control to the shell. The shell will then display the job number and status of the stopped process. To resume the process in the background, you can use the bg command with the job number or % sign. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-cli-jobs.html

The recommended file system for data volumes is XFS. XFS is a high-performance and scalable file system that supports large files and file systems, online defragmentation and resizing, metadata checksums, and other features. XFS is the default file system for data partitions in SLES 15. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/cha-filesystems.html#sec-filesystems-xfs

https://documentation.suse.com/ko-kr/sles/15-SP1/html/SLES-all/cha-network.html

The file that provides local name resolution is /etc/hosts. This file contains mappings of hostnames to IP addresses for hosts on the local network or hosts that are frequently accessed. The system will consult this file before querying DNS servers when resolving hostnames. This can improve performance and security, as well as provide fallback in case DNS servers are unavailable. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-network-dns.html#sec-network-dns-hosts