SUSE sca_sles15 - SUSE Certified Administrator in Enterprise Linux 15

The Linux kernel is started by the BIOS or UEFI firmware during the boot process, depending on the hardware architecture. The BIOS or UEFI firmware is responsible for initializing the hardware and loading the boot loader from a boot device. The boot loader then loads the kernel and passes some parameters to it. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-boot-process.html

The bash commands that result in a valid arithmetic expansion are:

TOTAL=$[8/2]

TOTAL=$((5+2))

((TOTAL++))

Arithmetic expansion is a bash feature that allows you to perform integer calculations and assign or use the result in a command or expression. There are two syntaxes for arithmetic expansion: [expression]and((expression)). The expression can contain variables, operators, parentheses, etc. The ((expression)) syntax can also be used without the $ sign for assignments or conditional tests. References: https://documentation.suse.com/sles/15-SP3/html/SLES-all/cha-bash.html#sec-bash-arithmetic

The program systemd is the process with process ID 1. It is responsible for initializing the system in the required way. systemd is started directly by the kernel and resists signal 9, which normally terminates processes. All other programs are either started directly by systemd or by one of its child processes.

The system initialization system used in SLES 15 is systemd. It is a modern and powerful system and service manager that replaces the traditional init system. It provides faster boot times, better dependency handling, parallelization, and more features and capabilities. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/cha-systemd-basics.html

https://www.gnu.org/software/bash/manual/htm l_node/Bash-Startup-Files.html

When Bash is invoked as an interactive login shell, or as a non-interactive shell with the --login option, it first reads and executes commands from the file /etc/profile, if that file exists. After reading that file, it looks for ~/.bash_profile, ~/.bash_login, and ~/.profile, in that order, and reads and executes commands from the first one that exists and is readable. The --noprofile option may be used when the shell is started to inhibit this behavior.

The first file executed by a bash login shell is /etc/profile. This file sets global environment variables and aliases for all users. It may also source other files in /etc/profile.d/ directory. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/cha-bash.html#sec-bash-startup

When you launch yast2 without specifying a module name, the YaST Control Center appears. The YaST Control Center is a graphical interface that allows you to access various YaST modules for system administration and configuration tasks. You can browse through different categories of modules, such as Software, Hardware, System, Network Services, etc., and launch them by clicking on their icons. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-yast.html#sec-yast-control-center

The program systemd is the process with process ID 1. It is responsible for initializing the system in the required way. systemd is started directly by the kernel and resists signal 9, which normally terminates processes. All other programs are either started directly by systemd or by one of its child processes.

https://documentation.suse.com/sles/15-GA/html/SLES-all/cha-systemd.html

Systemd is the first process that is started by the kernel during boot. It has the process ID of 1. It is responsible for initializing and managing other processes and services on the system. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/cha-systemd-basics.html#sec-systemd-intro

Assuming the default value for umask, which is 022, the permissions on new files would be set to 644 and the permissions on new directories would be set to 755. The umask value is subtracted from the base permissions of 666 for files and 777 for directories to determine the actual permissions. For example, 666 - 022 = 644 for files and 777 - 022 = 755 for directories. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-file-permissions.html#sec-file-permissions-umask

https://documentation.suse.com/sles/12-SP4/html/SLES-all/cha-security-acls.html

The three permissions available on posix file systems are read, write, and execute. The read permission allows the user to view the contents of a file or directory. The write permission allows the user to modify or delete a file or directory. The execute permission allows the user to run a file as a program or change into a directory. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-file-permissions.html#sec-file-permissions-types

SUSE Linux Enterprise Server supports two different kinds of VNC sessions: One-time sessions that “live” as long as the VNC connection from the client is kept up, and persistent sessions that “live” until they are explicitly terminated.

5.1 One-time VNC Sessions

5.2 Persistent VNC Sessions

https://documentation.suse.com/sles/11-SP4/html/SLES-all/cha-vnc.html#:~:text=SUSE%20Linux%20Enterprise%20Server%20supports,until%20they%20are%20explicitly%20terminated .

The statement that is true regarding the life cycle support for SUSE Linux platform products is that the support for SLE platforms has a 13 year life cycle: 10 years of general support and 3 years of extended support. General support includes security updates, bug fixes, feature enhancements, and technical support. Extended support includes security updates and technical support only. Service packs have a different life cycle depending on their release date and version. References:https://www.suse.com/lifecycle/