Process Management in Linux | System Administrator

Process management is an integral part of any modern-day operating system (OS). The OS must allocate resources to processes, enable processes to share and exchange information, protect the resources of each process from other processes and enable synchronization among processes. To meet these requirements, the OS must maintain a data structure for each process, which describes the state and resource ownership of that process, and which enables the OS to exert control over each process.

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Linux | Introduction To Memory Management.

Memory Hierarchy:

Memory Hierarchy gives the relationship between the speed, size and cost with respect to the distance from the Processor.

cpu111.png

In the diagram above the peak of the pyramid represents the processor. The Register lies with in the processor itself hence are the closest to the processor and work the fastest. But the number of registers that can be included in a processor is limited, as it would lead to increase in processor size, increase in manufacturing cost etc. Thus the register memory is restricted to minimal.

A level below the register is the L1 cache or the first level cache. In the processors of today, the L1 cache also lies on the processor chip itself, though it might lie outside too.
The cache memory works at a very fast speed but is also extremely expensive as compared to the other memories available. This high cost is one of the major restriction why we can not use lots of cache in a computer even though it is faster.
The general thumb rule is, higher the cache memory faster would be the working of the processor.

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Simple script to connect multipleFortiClient SSL VPN client

Introduction:-

The FortiGate unit supports both SSL and IPSec VPN technologies. Each combines encryption and VPN gateway functions to create private communication channels over the Internet, which helps to defray physical network costs. Both enable you to define and deploy network access and firewall policies using a single management tool. In addition, both support a simple client/user authentication process (including optional X.509 security certificates). You have the freedom to use both technologies; however, one may be better suited to the requirements of your situation.

In general, IPSec VPNs are a good choice for site-to-site connections where appliance-based firewalls are used to provide network protection, and company sanctioned client computers are issued to users. SSL VPNs are a good choice for roaming users who depend on a wide variety of thin-client computers to access enterprise applications and/or company resources from a remote location.

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Virtualization – Introduction – (Containerization)-setup-LXC

Introduction:-

What does Virtualization mean?

The simple explanation is that you create a virtual version of something that’s generally used for some type of execution. For example, if you were to partition a basic hard drive to create two hard drives, then they would be two ‘virtualized hard drives,’ as the hardware is technically a single hard drive that was digitally separated into two.Virtualization refers to the creation of a virtual resource such as a server, desktop, operating system, file, storage or network.

what are Containers?

Containers are a lightweight virtualization technology.In IT it is all about the need to run an application, not a virtual machine.In the end, it is the application user that has a need.This need is to run the application and no user will ever ask for a virtual machine.That is exactly one of the major design goals of the container technology.

A container is a virtualization method at the OS level.This allows multiple instances of an os to be running on the same kernel, which allows for a more efficient usage of available resources.

Try Container Online Click Here 

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WordPress-installation-using-bash-script-with-nginx-web-server

What is WordPress?

WordPress is a free and open-source content management system (CMS) based on PHP and MySQL.[5] WordPress is installed on a web server that is either part of an Internet hosting service or a network host in its own right. The first case may be a service like WordPress.com, for example, and the second case could be a computer running the software package WordPress.org.[6] A local computer may be used for single-user testing and learning purposes.

WordPress has a web template system using a template processor. Its architecture is a front controller, routing all requests for non-static URIs to a single PHP file which parses the URI and identifies the target page. Once downloaded, WordPress installation files have a size of about 20 MB.

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Alternative for DD command with a progress report about how much has been written-dcfldd

1 ) DD Command:-

The dd command stands for “data duplicator” and used for copying and converting data. It is very powerful low level utility of Linux which can do much more like.

• Backup and restore the entire hard disk or partition.
• Backup of MBR (Master Boot Record)
• It can copy and convert magnetic tape format, convert between ASCII and EBCDIC formats,swap bytes and can also convert lower case to upper case.
• It can also be used by Linux kernel make files to make boot images.

Only superuser can run this command because you can face a big data loss due to its improper usage, so you should be very careful while working with this utility. At that moment data loss can convert the dd utility as a “data destroyer” for you

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