The operating systems Linux®, Macintosh® (Mac) and Microsoft® Windows® are the main software to every computer system to run properly along with other hardware. These operating systems (OS's) are very different in several ways, but they also have some similarities too. Linux, Mac and Windows use memory management, process management, file management and security management to operate the computer systems correctly.
The first management to compare and contrast between the three OS is memory management. Memory management is a process of handling computer memory to different programs to operate a system effectively. This type of management in computers involves storing physical data using RAM, chips, memory caches and virtual memory. The largest similarity between the three is they help manage the memory to optimize performance in a system.
The difference between the three is the dissimilar ways they handle the memory.For example, one OS may use virtual memory only, or another OS may use physical and virtual memory together. Linux memory management has a 32 and 64 bit addresses to store memory. Linux uses paging to manage their memory. The 32 bit uses 4 GB data, and the 64 bit uses 2 petabytes of data.
The way the paging works for Linux is it has three levels of types of pages called page global directory, page middle directory and page tables. Two of the pages are the main ones used, but the page middle directory has one entry. The Linux OS splits the 4 GB address space into the 3 GB where it finishes or processes the data.Windows uses very different memory management than Linux.
It uses a virtual memory manager, lazy allocation, prefetching and page file. The virtual memory manager is responsible for organizing the memory. The lazy allocation is to avoid allocating memory that is not needed. Prefetching moves pages from disk to memory.
Pagefile stores the pages are too big to fit in the main memory. Windows also uses 32 bit, and 64 bit virtual address space like Linux. The 64 bit is the space, which Linux had the 2 petabytes. Windows memory goes from page directory register to page directory table. Then it goes into page table where it is then saved in page frames to a physical address.
Linux goes through one extra table before it is sent into the page frame with a physical address.Mac OS does things a little differently than Linux and Windows. Mac has over 4 GB of space, which uses 32 bit of addressable space per process. It also provides 18 exabytes in a 64 bit addressable space. The Mac OS barely uses RAM memory to move memory around to complete tasks.
It uses a hard disk for all the memory that is not being used which this gives the processes the entire address space to complete processes. Mac uses paging to complete processes as well. Each page has 4 kilobyte. Wired Memory is also something Mac uses that contains about 17 megabytes to a 128 megabyte system. Typically, Mac has more memory in their OS to move memory around.
Process ManagementProcess management in Linux, Windows, and Mac are similar in that you need to understand each process, what it is, and who or what is using the process before you make any attempt to stop the process. Each system has a different way to interact with running processes. For example, if you were to look at the running processes in Linux you could issue the top command or the ps command, from the command line. In Windows you could use the Task Manager or Windows Process Explorer to view the running processes. On a Mac, you could use ps from a terminal window or use the GUI task manager. Unlike Mac and Linux, the Windows task manager does not show the process ID (PID) by default, you need to enable the option manually, to view the PID.
Linux Process ManagementLinux is a multi-user operating system, which means multiple users can use the OS at the time without any issues. However, each user does not have to be logged into the system for a process to be running with their user. The user could be running a service or daemon that will continue running when the user is no longer logged into the system. Generally, users cannot modify processes that are being run by other users, the root (system administrator) user or the process owner would have to modify any process. However, some users can be granted special permissions to be able to modify the processes of others, if the system administrator would like to give them that permission.
Mac Process ManagementBecause Mac is a BSD-style operating system, it is also a multi-user operating system. However, since Mac is more of a desktop OS, it is not common to see many users accessing the system at the same time. In spite of this, the process management in Mac is very similar to Linux because they are both UNIX-based operating systems. One key difference is that with Mac most people would modify and control processes from with the GUI and most users would modify the processes using ps on Linux.Windows Process ManagementIn general, Windows is not a multi-user operating system, unless it is a Windows Terminal Server, meaning that it was not designed to handle more than one user at a time, whereas Linux and Mac are both multi-user operating systems and is capable of handling multiple users at a time.
Windows however, can run multiple processes as different users concurrently. With all three operating systems, users cannot terminate or modify the process priority for other users; the system administrator can only do this. Each user can modify the process they own in various ways. For example, if a process is using too much memory or CPU on the system, but it is not a critical process, the user can change the priority of the process so it will use less memory or CPU.
File ManagementFile management goes by different names such as file system but what it is it? Well, it is “the system that an operating system or program uses to organize and keep track of files.” There are three types of operating systems used in most modern day computers and that is Mac OS X Lion, Windows 7 or 8, and Linux. Each one of these types of operating systems has their own unique system of file management but some of them have some things in common.Linux/UnixThe Unix-like operating system creates a virtual file system. In this system, you will have all the files show up under a single hierarchy system.
Under this type of system, all files extend off its rood directory. This means that there is no system of “drives” like c: or d: used but only a root directory which uses the “/”. Device names are given to each device but under this system of management, this is not how the files are accessed on the device. The operating system must be informed where in the directory tree those files are in order to gain access to file on the other devices.
The process is known as the mounting a file system and usually the administrator, also known as the root user, may authorize the mounting of file systems. The Linux system is based off the UNIX and is really one and the same.This system uses Unicode to store filenames and they can have up to 255 characters in those names. The system also uses three types of links known as Unix-style hard links, symbolic links, and aliases. Mac OS X’s newer versions have had their capabilities increase in what they can do.
They have the ability to read and write to the legacy FAT file systems like FAT16 and FAT32 which is often used by the Windows OS. The Mac OS X version 10.6 has the capability of even reading and writing to the other type of system that Windows uses and that is the NTFS. This allows for the easier transferring of information between the two operating systems.WindowsThe Windows Operating system uses four types of file management systems. These systems are… FAT NTFS exFAT ReFS The ReFS file system is only supported and usable in Windows Servers 2012 and the system cannot boot from this system.
Windows OS make using any file management easier by utilizing it Explorer program as the primary file manager for the operating system.The FAT file system is supported by most of the operating system that can be found in modern personal computers ranging all the way back to DOS. The FAT system has been expanding from FAT12, FAT16, and to what we have today FAT32. The FAT32 has a file limit close to 4 GB but it addressed the limitations that the other FAT systems had. The file names in this system have an eight-character limit to them and extensions are only allowed three for example .exe.
When Windows 95 and Windows NT came out the VFAT option allowed longer file names to be stored in the system.The other system used is the NTFS or New Technology File System was introduced with the Windows NT OS. This system has features like hard links, multiple file streams, attribute indexing, quota tracking, sparse files, encryption, and compression and reparses points. This system can be read and written to by all three of the major operating system like Linux, Mac OS X, and Windows.
This system allows for more flexibility than some of the other systems used by the other operating systems and is more powerful. Let alone all the other features in this system it also has better recoverability, security and large disks and files.All the operating system be it Mac, Linux, or Windows have a different approach to how they want to manage their files. Each one has their own advantages for example Mac's system not having to have an exterior defragmenting system, and the Windows system being larger and more flexible than that of the rest. With those things also come the disadvantages of the system.According to Sun Tzu, “The art of war teaches us to rely on the likelihood of the enemy's not coming, but on our own readiness to receive him; not on the chance of his not attacking, but rather on the fact that we have made our position unassailable.
” This section of the paper discusses the security management of the three operating systems. What is security management? According to Microsoft, “security management capabilities presented in a clear, interactive format help customers control access to data, applications, and tools, reduce IT administration, and maintain high levels of protection for a business system.” (Microsoft, 2007).It is the responsibility of everyone, users, managers and technicians to ensure that their operating systems are properly protected by downloading patches and definitions and making sure they are installed. Management needs to confirm users are properly trained in the workplace safeguarding business computers and guaranteeing they are properly secured.Windows Overview Security ManagementFor this section of the paper, we addressing Windows 7 for comparison with the other OS unless specifically mention another version.
When anyone turns on Windows for the first time, the Windows OS will query the user for a user-name and a password, which is optional. These credentials are associated with the access validation while performing specific processes within the OS based on the permissions set by the administrator, network or otherwise. According to an article, written Linux vs. Windows: Which is Most Secure? by Kenneth van Wyk, “an application will open a reference to a secured object.
Windows then verifies that the object's security descriptor grants the process of the requested access and then the system will cache the granted access rights.”Linux Overview Security ManagementMost Linux systems work with either RPM (RedHat Package Manager, this is used by Mandrake and Suse as well), apt/dpkg (Debian Package Manager), or YUM (Yellowdog Linux Manager). You can update specific software individually using these commands, or use your vendor's updating tools if available. RPM has a well-managed support option available through the RPM Network that can help users manage various RedHat servers. The managed support option uses the update command, which will automatically resolve dependencies.
Manual updates from rpm files can be frustrating since the RPM command only reports on dependencies. (Evans, Homsher)Mac Overview Security ManagementAs Mac OS X, systems continue to move onto corporate desktops, IT managers are looking for a way to accommodate their users' choice of that platform without having to add additional management infrastructure and hire or train additional staff to learn and work effectively in a work environment. Since IT desktop support personnel can locally manage the settings for security, desktop and application used by Windows users that use the Group Policy, sometimes the Macs are still being manage for each individual computer. Security issues, such as turning off Internet sharing, may be missed by employees who do not have extensive Mac domain experience.
This brings up the point earlier in this section about having additional IT folks or training the workforce. Modularity within the system is strong capability of architectural security within Linux, but is lacking in Microsoft Windows. There are applications that tie into every major part of the MS Windows system in such a promiscuous fashion that something as apparently trivial as a browser exploit can actually reach into kernel space and from there affect the entire system. The Windows Update and the Action Center are both defaulted update tools for as of Windows versions XP with Service Pack Two (SP2) and later versions. From the perspective of an end-user seeking to keep his computer up to date with the current vendor-supplied security patches, Windows sure does make things easy.
When we look at all three of the operating systems and compare there similarities and differences what we discover is they are all very similar in how they use memory management, process management, file management and security management to operate the computer systems correctly. When deciding which operating system to use, it really comes down to how the customer is going to be using it.
