10+ Nova Gas Techniques Interview Questions and Answers

GRUB is a bootloader for Linux systems, managing the boot process and allowing OS selection.

• GRUB stands for Grand Unified Bootloader, responsible for loading the operating system.

• It allows users to select between multiple operating systems at boot time.

• GRUB configuration files are typically located in /boot/grub/ or /etc/grub.d/.

• To check disk space, use the command 'df -h' for human-readable output.

• The 'du -sh /path/to/directory' command shows the size of a specific directory...read more

Nginx is a high-performance web server and reverse proxy server known for its speed and efficiency.

• Nginx can be configured to log requests and errors using the 'access_log' and 'error_log' directives.

• Access logs can be customized with different formats using the 'log_format' directive.

• Example of access log configuration: 'access_log /var/log/nginx/access.log;'.

• Example of error log configuration: 'error_log /var/log/nginx/error.log warn;'.

• Logs can be rotated using tools like '...read more

MySQL uses port 3306, while SSH operates on port 22 by default for secure remote access.

• MySQL default port: 3306 - used for database connections.

• SSH default port: 22 - used for secure shell access.

• Both ports can be changed in configuration files if needed.

• Example: MySQL config file (my.cnf) can specify a different port.

• Example: SSH config file (sshd_config) can also specify a different port.

Top 10 Linux command-line commands for system management and navigation.

• 1. ls - Lists files and directories in the current directory. Example: 'ls -l' for detailed listing.

• 2. cd - Changes the current directory. Example: 'cd /home/user' to navigate to the user's home directory.

• 3. cp - Copies files or directories. Example: 'cp file.txt /backup/' to copy file.txt to the backup directory.

• 4. mv - Moves or renames files or directories. Example: 'mv oldname.txt newname.txt' to renam...read more

Apache Tomcat is an open-source web server and servlet container for running Java applications.

• Developed by the Apache Software Foundation.

• Primarily used to serve Java Servlets and JSP (JavaServer Pages).

• Supports various Java EE specifications, including Servlet and JSP.

• Can be integrated with other web servers like Apache HTTP Server.

• Commonly used in enterprise applications for web-based services.

Linux firewall rules control network traffic using tools like iptables and firewalld, enhancing system security.

• Iptables: A user-space utility that allows a system administrator to configure the IP packet filter rules of the Linux kernel.

• Example: 'iptables -A INPUT -p tcp --dport 22 -j ACCEPT' allows SSH traffic.

• Firewalld: A dynamic firewall management tool that supports zones and services.

• Example: 'firewall-cmd --zone=public --add-service=http' allows HTTP traffic in the pub...read more

A zombie process is a terminated process that still has an entry in the process table, waiting for its parent to read its exit status.

• Zombie processes occur when a child process has completed execution but its parent process hasn't read its exit status.

• They are created when a process terminates, but the parent process has not yet called wait() to collect the exit status.

• Zombie processes consume system resources, but they do not consume CPU or memory resources.

• Example: If a pa...read more

Data query language is used to retrieve data from a database, while data definition language is used to define and modify the structure of a database.

• Data query language (DQL) is used to retrieve data from a database, such as SQL SELECT statement.

• Data definition language (DDL) is used to define and modify the structure of a database, such as SQL CREATE TABLE statement.

• DQL focuses on querying and retrieving data, while DDL focuses on defining and modifying the database schema....read more

Object-oriented programming concepts from class to multi-threading in Android development.

• Class: blueprint for creating objects, encapsulates data and behavior (methods)

• Inheritance: allows a class to inherit properties and methods from another class

• Polymorphism: ability for objects to take on multiple forms

• Abstraction: hiding implementation details and showing only necessary features

• Encapsulation: bundling data and methods that operate on the data into a single unit

• Interfaces...read more

I have extensive knowledge on system use.

• Proficient in using various operating systems such as Windows, Mac OS, and Linux

• Familiar with different software applications such as Microsoft Office Suite, Adobe Creative Suite, and Google Suite

• Experience in troubleshooting technical issues and providing solutions

• Knowledgeable in network systems and security protocols

• Ability to adapt to new systems and software quickly

Array list implementation involves creating a dynamic list that can grow or shrink in size.

• Use ArrayList class in Java to create an array list of strings.

• ArrayList<String> list = new ArrayList<>();

• Add elements to the list using list.add() method.

• list.add("Apple");

• Access elements using list.get() method.

• String fruit = list.get(0);

• Remove elements using list.remove() method.

• list.remove(0);

SDLC is the Software Development Life Cycle, while STLC is the Software Testing Life Cycle.

• SDLC focuses on the development of software from planning to deployment, while STLC focuses on the testing activities within the SDLC.

• SDLC includes phases like requirements gathering, design, coding, testing, and deployment, while STLC includes phases like test planning, test design, test execution, and test closure.

• SDLC is more comprehensive and covers the entire software development p...read more