Operating System: Core Features, Memory Management And Security

1: Introduction

The most common OS nowadays are Microsoft Windows, Mac OS and Linux. Different OS plays different roles and different characteristics. Windows is now a user-friendly operating system. Mac OS is an operating system that runs on the Macintosh series of Apple and is the first popular commercially available graphical user interface operating system. Linux is a Unix-like operating system that is free and distributed freely.

2: Operating System & core features

An Operating System is an integral part of virtually every computer system. It fundamentally affects how you can use your computer. (Parsons, 2011) In addition, Operating System is the main interface between software and hardware. It also manages the resource of the system and controls the execution of applications. (Sterling, et al., 2018b) Microsoft Windows is still the most universal OS in the world and it is also the most familiar OS for most of people. Microsoft Windows is around 80% in the desktop operating system market over the world and over 80% in Asia in 2019. (StatCounter Global Stats, 2019) The latest stable version of the Windows operating system is Windows 10 which was released on July 29, 2015. The below review is based on Windows and the focus of the review are on the features of memory management, security and file system.

2.1: Memory management

Memory management is a main feature of operating system. And memory management in operating systems is the role responsible for managing the primary memory of the computer. Primary storage is the only one that can access to CPU directly. Such as RAM is one of the primary storages. Its size is small and light but it is expensive. Moreover, RAM is random access, volatility and with a high read and write speed.

Memory management tasks keep track that which parts of memory are currently being used and who is using, determine and control the processes and data to transfer under memory, and assign and delete memory space as required. (Silberschatz, Galvin and Gagne, 2013)

Memory management also performs performance enhancements, multiple processes execution, and data storage optimization. It helps to improve computer system efficiency. Because of computer system memory management, the computer system remains stable, resulting in good performance. Memory management allows multiple processes to be executed concurrently in the computer system. Memory management uses the same memory space between different processes. (Shukla, 2017)

For example, the Windows virtual memory manager controls how memory is allocated and how paging is performed. (Stallings, 2012) In-Memory Manager, Windows 10 added a new concept called a compression store that is a compressed page set in memory. This means that when Memory Manager feels memory pressure, unused pages will be compressed rather than written to the disk. This reduces the amount of memory used per process, enabling Windows 10 to keep more programs in physical memory at a time. This also helps to make Windows 10 more responsive. The compression store resides within the working set of the system process Because the system process keeps the store in memory, its working set increases as storage is made available for other processes. This is evident in the Task Manager and it appears that the system process uses more resources than previous releases. (Aul, 2015) A good memory management in the OS can allow more applications run at the same time and the computer does not need the always restart to release memory.

2.2: Security

Security management protects computer system data from the different threats and attacks on viruses. To ensure compute system security, an operating system uses various techniques such as encryption, authorisation, cryptography, etc. For keeping information protected, computer security is important. It is also vital for the overall health of the computer; proper computer protection helps prevent viruses and malware, which facilitates faster and smoother running of programs.

The basic goals of information security are often outlined in three universal concepts known as the CIA which are confidentiality, integrity, and availability. (Cabric, 2015)

For confidentiality, Windows has several built-in groups that are generated when we installed the operating system. (Shinder, Shinder and Grasdal, 2002) Windows system uses a name and password scheme to authenticate the user when a user logs in to a Windows system. If the logon is approved, the system will create a process for user and associate an access token with the process object. The access token, whose specifics are later described, contains a security ID (SID), which is the identifier for security purposes by which this user is known to the system. The new process object inherits the same access token when any additional processes are spawned by the initial user process.

Checksum is an example for integrity in CIA. A checksum is a series of numbers and letters used for error checking information. Performance can be enhanced by this approach compared to previous similar systems without significantly reducing the sophistication of the attack. Also a method by which this technique can be easily implemented into any system is also provided to allow it to check its own reliability and the validity of its data files. (Cohen, 1987)

Availability ensures timely and uninterrupted access to the data in the system and the network by the authorized users of a system. (Brook, 2019) RAID is a good example in the aspect. RAID offers fault tolerance by using multiple. The most common RAID that people using are RAID 0, RAID 1 and RAID 5. RAID 0 is for extend the virtual hard disk. RAID 1 is a mirror backup method. RAID 5 is used for file storage effectively.

Therefore, the examples of Windows operating system that achieve CIA principles which are access control, checksum and RAID.

For the place I am working, we have set different access control right for different folders and printers. A role-based access control implements job function or responsibility-based access control. Moreover, we use Symantec Endpoint Protection as the antivirus. We have to keep the antivirus program up-to-date for ensuring the virus definitions are the latest to prevent virus or malware. The antivirus program will block the suspicious connection or executable file before end users access it. We had enabled BitLocker for all PCs for encrypting the hard disk. BitLocker is a full volume encryption feature in Windows. It protects data by AES encryption algorithm. Moreover, we use McAfee products for file encryption, end users can encrypt and decrypt files by their selection. Also we use hardware encryption USB devices and blocked all USB devices which are not registered or approved to enhance security. Furthermore, we are using RAID 5 setup for backup for the file sharing server.

2.3: File systems

Using the file system to control how to store and retrieve data. Stored data would not be separated into individual files without a file system and would be difficult to identify and retrieve. The organization and availability of each files becomes even more important in data storage as data capacities increasing. A file system stores and organizes data, and all the data contained in a storage device can be considered as a type of index. These devices may include hard drives, USB flash drives and optical drives. (Carrier, 2005)

Those files in the folders and the index contains the File Allocation Table information which we named FAT. The Microsoft Windows Operating System follows the File Allocation Table. FAT is considered easy and consistent and is built on legacy file systems. FAT was designed for floppy disks in 1977, but was later adapted for hard drives. Although powerful and compatible with most current Operating systems, FAT is unable to follow the steps to the latest file systems. Nowadays we usually use NTFS be the file management system which is New Technology File System and it is the latest file management system of Windows. Since NTFS can store lots information of files such as owner names, file permissions, creation time, access time and modify time. (Sterling, 2018a)

In the FAT family, we have FAT12, FAT 16 and FAT32. The most common one is FAT32. FAT32 is compatible with different OS each as Windows, Mac and Linux and applied in many embedded smart experience industries such as smart cars or smart homes. However, NTFS on compatible with Windows and support read-only in some Linux systems and some USB expansion storage devices such as game consoles may not support NTFS. Secondly, the file size limitation is also different. The maximum file size is 4GB and the maximum split slot size is 2TB in FAT32 but there is no actual file size or slit slot size limit in NTFS. It is not difficult to see that NTFS is significantly more powerful then FAT32. It is more suitable for large-capacity disks and split slots. It has the advantages of higher disk utilization, better security and stability, and determines NTFS. Moreover, NTFS is a more flexible file system. Therefore, NTFS file system is the best choice for Windows system. Although FAT32 has the widest platform compatibility, this format is too old, not only lacks the features that meet the characteristics of the times, but also the read and write performance is relatively backward, except for small-capacity USB flash drive that can be used for device compatibility. In addition, it is not recommend in Windows system.

3: Summary

The Operating System is responsible for providing an interface for users to communicate directions to perform specific tasks on a computer. By managing common hardware functions, the OS facilitates the above process by converting simple directions into detailed instructions that can be interpreted by the computer. In addition, the OS handles storage and processing tasks that enable users to store and request data, run more than one application at a time, and even enable multiple users to access the same device. Finally, by controlling the resource allocation and information, the OS secures user files, allowing users to securely share their machine and networking resources with others. The computer is said to be useless and incapable of performing without the OS.