Operating System Articles - Page 157 of 171

lsblk command is used to display a list of information about all available block devices. However, it does not give a list of information about RAM disks. Examples of block devices are hard disk, flash drives, CD-ROM. This article explains about how to find a list of block devices in Linux Machine.To install lsblk for Fedora and CentOS ,use the following command –$ sudo yum install util-linux-ngTo install lsblk for Ubuntu and Linux Mint ,use the following command –$ sudo apt-get install util-linux -yTo find the default list of all blocks, use the following command –$ lsblkThe sample output should be like ... Read More

nslookup is a network administration command-line tool available for many computer operating systems for querying Domain Name System (DNS) to obtain domain name or IP address mapping or for any other specific DNS record. This article explains about nslookup command in detail. Nslookup can be run in two modes, Interactive and Non-Interactive. The Interactive mode is used to query DNS-Server about various domains and hosts. Non-Interactive mode is used to query about information of a domain or host.To find out Find out “A” record (IP address) of Domain, use the following command –$ sudo nslookup tutorialspoint.comThe sample output should be ... Read More

In this article, we will learn about the ‘date’ command in Linux and how to practically use the ‘date’ command in day-to-day usage with some practical examples. The ‘date’ command is used to print or to change the system date and time.General Syntax[root@localhost ~]# date [OPTION]... [+FORMAT] [root@localhost ~]# date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]The Date Command has the following UsagesWe can print date and time on the systemWe can display the date and time in the given format.We can read the date from the fileWe can display the Universal time.We can set the system date and time.Displaying the Date and Time from ... Read More

People who have been using windows operating system usually encounter persistent messages to upgrade to Windows 10. The good news is that, upgrading to Windows 10 is now free. But in case of Apple, it allows its users to upgrade to newest operating system for free at any point. If users delay, they might land themselves in trouble as Windows is taking a very different approach.All those who have not upgraded their system to Windows 10 by June 29, 2016, they need to spend about $119. And those who consider, the cost of upgradation is more than they can handle. ... Read More

Processes that executing concurrently in the operating system may be either independent processes or cooperating processes. if a process cannot affect or be affected by the other processes executing in the system then the process is said to be independent. So any process that does not share any data with any other process is independent. A process is said to be cooperating if it can affect or be affected by the other processes executing in the system. So it is clear that, any process which shares its data with other processes is a cooperating process.There are many reasons for providing ... Read More

One may be amazed how the CPU is programmed. A special register is contained in CPU-the instruction register-whose bit pattern determines what the CPU will do. Once that action has been completed, the bit pattern in the instruction register can be changed, and the CPU will perform the operation specified by this next bit pattern.Most of the modern CPUs use an instruction queue. Some instructions are waiting in the queue, ready to be executed. Different electronic circuitry keeps the instruction queue full while the control unit is executing the instructions. But this is simply an implementation details that allows the ... Read More

If several processes are suspended on condition x, and an x.signal() operation is executed by some process, then we can determine that which of the suspended processes should be resumed next by one simple solution is to use a first-come, first-served (FCFS) ordering, so that the process that has been waiting the longest is resumed first. In many circumstances, however, such a simple scheduling scheme is not adequate. For this reason, the conditional-wait construct can be used. This construct has the formx.wait(c);Here c is an integer expression that is evaluated when the wait() operation is executed. The value of c, ... Read More

Peterson’s solution provides a good algorithmic description of solving the critical-section problem and illustrates some of the complexities involved in designing software that addresses the requirements of mutual exclusion, progress, and bounded waiting.do {    flag[i] = true;    turn = j;    while (flag[j] && turn == j);    /* critical section */    flag[i] = false;    /* remainder section */ } while (true);The structure of process Pi in Peterson’s solution. This solution is restricted to two processes that alternate execution between their critical sections and remainder sections. The processes are numbered P0 and P1. We use Pj ... Read More

In Synchronization hardware, we explore several more solutions to the critical-section problem using techniques ranging from hardware to software based APIs available to application programmers. These solutions are based on the premise of locking; however, the design of such locks can be quite sophisticated.These Hardware features can make any programming task easier and improve system efficiency. Here, we present some simple hardware instructions that are available on many systems and show how they can be used effectively in solving the critical-section problem. If we could prevent interrupts from occurring while a shared variable was being modified. The critical-section problem could ... Read More

Windows implements the Windows API, which is the primary API for the family of Microsoft operating systems (Windows 98, NT, 2000, and XP, as well as Windows 7). Basically A Windows application runs as a separate process, and each process may contain one or more threads. Additionally, Windows uses the one-to-one mapping, where each user-level thread maps to an associated kernel thread. The general components of a thread include −A thread ID uniquely identifying the threadA set of register representing the status of the processorA stack of user, employed when the thread is running in user mode, and a kernel ... Read More