System Administration Core Concepts and Administration Tasks Flashcards
Name FIVE critical issues that can happen from poor system administration.
vulnerable to attacks, downtime of servers, data loss, violation to compliance and standards, poor resource utilisation, lack of scalability.
What does lack of scalability mean, with regard to system administration?
Difficult for the organization to grow and adapt to changing business needs.
In terms of system administration, poor compliance results in _____________________________________
possible legal and financial penalties, as well as damage to the organization’s reputation.
What does the crontab entry 0 5 1 /3 * rm -rf /tmp/users/ do?
0 5: The cron job will run at 5am in the morning.
1: The cron job will run on the first day of the month.
*/3: The cron job will run every three months (i.e., once every quarter).
: The cron job will run every month.
rm -rf /tmp/users/: remove all files and directories inside the /tmp/users directory using the rm command with the -rf options.
Differentiate between the su and sudo command.
su, short for “switch user,” is a command that allows you to switch to another user account, including the root account. When you run su, you are prompted to enter the password for the account you want to switch to. Once you’ve entered the correct password, you are logged in as that user and have access to their permissions and privileges.
sudo, short for “superuser do,” is a command that allows you to execute commands with the privileges of another user, typically the root account. When you run a command with sudo, you are prompted to enter your own password, not the password for the account you want to switch to. If your user account is authorized to run commands with sudo, the command is executed with elevated privileges.
What are the benefits of the cron utility?
Backup: A system administrator can use crontab to schedule regular backups of important files and directories on the system.
Maintenance: Crontab can be used to schedule regular system maintenance tasks such as cleaning up temporary files, updating system software, and running security checks.
Monitoring: System administrators can use crontab to schedule scripts that monitor system logs, check disk usage, or monitor network traffic.
Reporting: Crontab can be used to schedule scripts that generate periodic reports on system activity, such as usage statistics or error logs.
Automation: System administrators can use crontab to automate repetitive tasks such as file transfers, database updates, or system upgrades.
Assess the advantages of SELinux
Enhanced security: SELinux provides an additional layer of security to the Linux system by enforcing mandatory access controls (MAC) on all processes and files. It allows administrators to define and enforce access policies based on a user’s role or context, rather than just the traditional user/group/other permissions model.
Reduced system vulnerability: By default, SELinux sets all processes to run with the lowest level of privilege required to perform their specific task, which greatly reduces the attack surface and system vulnerability. This ensures that if an attacker does manage to exploit a vulnerability, the damage is limited to a specific process or application and does not spread across the system.
Improved auditing and logging: SELinux provides detailed logs of all system activity, including attempted access violations, which can be used to investigate and diagnose system problems or security breaches.
Flexibility: SELinux is highly configurable, allowing administrators to customize policies to fit their specific needs. This flexibility allows organizations to adapt the security policies to their unique requirements.
Open-source nature: SELinux is an open-source project that is constantly being updated and improved by the community. This means that security issues are quickly identified and addressed, and users can benefit from a robust, well-supported security solution.
Assess the disadvantages of SELinux
Complexity: SELinux policies can be complex and difficult to understand, especially for users who are not familiar with MAC systems. Configuring and troubleshooting SELinux policies can be time-consuming and requires a significant amount of expertise.
Compatibility issues: In some cases, SELinux policies may interfere with the normal operation of applications or services. This can be particularly problematic for legacy applications that were not designed with SELinux in mind.
False positives: In some cases, SELinux may generate false positives, which can cause applications to be denied access to resources they legitimately require. This can lead to frustration for users and potential productivity loss.
Additional overhead: Enforcing mandatory access controls requires additional system resources, which can lead to performance degradation, particularly on systems with limited resources.
Limited user awareness: While SELinux provides enhanced security, it does not necessarily provide feedback to users in a way that is easily understandable. This can lead to confusion and frustration, particularly for less technical users.
A system administrator is required to manage processes. Explain the tasks performed here.
A system administrator is responsible for managing user accounts on the network, which includes creating and deleting user accounts, assigning permissions and access levels, and resetting passwords.
o For example, a system administrator might create a new user account for a new employee in the organization and grant them access to the appropriate systems and resources.
Backup and recovery is important in system administration. Why is it important and what tasks are invloved?
A system administrator is responsible for managing backups and ensuring that data can be recovered in the event of a system failure or data loss.
This includes setting up backup schedules, testing backups regularly, and restoring data when necessary.
For example, a system administrator might restore a database from a backup after a server failure.
A system administrator is required to manage security. Explain further.
A system administrator is responsible for ensuring the security of the network and its resources.
This includes monitoring the network for security breaches, implementing security measures such as firewalls and antivirus software, and educating users on security best practices.
For example, a system administrator might install a firewall to protect the network from external threats or train users on how to create secure passwords.
What is the rescue mode in an operating system?
Rescue mode is a specialized boot option in an operating system that is designed to provide a minimal environment with basic system utilities for troubleshooting and repairing the system when it fails to boot normally.
When a system is unable to boot or experiences other critical problems, the rescue mode allows the user to access the file system, diagnose and fix errors, and recover data. It typically loads a limited set of drivers, utilities, and services that are essential for system maintenance and repair.
How can the rescue mode assist in data recovery?
In the event of a system crash or hardware failure, rescue mode can help recover important data that may have been lost or corrupted. By accessing the file system, users can copy files to an external storage device or backup media.
