However, other users who are already accustomed to using GUI find it difficult to remember commands including attributes that come with it. GUI, or Graphical User Interface, make use of images and icons that users click and manipulate as a way of communicating with the computer. Instead of having to remember and type commands, the use of graphical elements makes it easier to interact with the system, as well as adding more attraction through images, icons, and colors.
To open the default shell which is where the command prompt can be found , press Ctrl-Alt-F1. This will provide a command line interface CLI from which you can run commands as needed.
You should see a line starting something like Mem: , etc. This is the total memory Linux thinks it has available to use.
The preferred size for a swap partition is twice the amount of physical memory available on the system. If this is not possible, then the minimum size should be the same as the amount of memory installed. Symbolic links act similarly to shortcuts in Windows. Such links point to programs, files or directories. It also allows you instant access to it without having to go directly to the entire pathname. Yes, it does. Just like Windows, you can use this key combination to perform a system restart.
In Linux, each drive and device have different designations. Assuming you are the system administrator or the owner of a file or directory, you can grant permission using the chmod command. TXT, which is assigned to groups and others. Linux assigns numbers at the end of the drive identifier. Hard links point directly to the physical file on disk, and not on the pathname. This means that if you rename or move the original file, the link will not break since the link is for the file itself, not the path where the file is located.
Any filename can have a maximum of characters. This limit does not include the path name, so therefore the entire pathname and filename could well exceed characters. In general, filenames that are preceded by a dot are hidden files.
These files can be configuration files that hold important data or setup info. Setting these files as hidden makes it less likely to be accidentally deleted. This serves as an alternative to minimizing and maximizing different windows on the current desktop. Using virtual desktops can clear the desktop when you can open one or more programs.
To share a program across different virtual desktops, in the upper left-hand corner of a program window look for an icon that looks like a pushpin. Find out more about OverDrive accounts. Arshad Iqbal. Bushra Arshad.
Operating systems quick study guide provides verbal, quantitative, and analytical reasoning past question papers, solved MCQs. Consider an extremely noisy channel in which the value of the signal to noise ratio is almost zero.
Calculate the capacity C of this channel. A Bit Map Protocol. Unacknowledged Connectionless Service. Connection-Oriented Service. Forward error correction. Simplest or Simplex. Stop-and-Wait Automatic Repeat Request. Q What are the methods for Handling Deadlocks states? Answer Q we can deal with the deadlock problem in one of three ways: 1 We can use a protocol to prevent or avoid deadlocks. Q How can we prevent the occurrence of a deadlock occurs?
Answer Q By ensuring that at least one of deadlock conditions cannot hold. As follow: 1 Mutual Exclusion: The mutual-exclusion condition must hold for non-sharable resources. If a process is holding some resources and requests another resource that cannot be immediately allocated to it the process must wait , then all resources currently being held are preempted. Answer For avoiding deadlocks is to require additional information about how resources are to be requested.
Each request requires the following: 1 The resource currently available. The above information is used to decide whether the current request can be satisfied or must wait to avoid a possible future deadlock. A deadlock-avoidance algorithm dynamically examines the resource-allocation state to ensure that a circular wait condition can never exist.
The resource-allocation state is defined by the number of available and allocated resources and the maximum demands of the processes.
Q Explain the deadlock detection? Answer Q If a system does not employ either a deadlock-prevention or a deadlock avoidance algorithm then a deadlock situation may occur. The system must provide: 1. An algorithm that examines the state of the system to determine whether a deadlock has occurred. An algorithm to recover from the deadlock. A detection and recovery will incur a considerable overhead in computation time that includes: 1 Run time cost of maintaining the necessary information.
Q How can recovery from deadlock state? Answer When a deadlock exists, several alternatives are available. One possibility is to inform the operator that a deadlock has occurred and to let the operator deal with the deadlock manually.
The system recovers from the deadlock automatically. There are two options for breaking a deadlock. A Process Termination: Aborting processes to eliminate the deadlock.
There are two methods: 1 Abort all deadlocked processes. B Resource Preemption: preempt: some resources from processes and give these resources to other processes until the deadlock cycle is broken.
Which resources and which processes are to be preempted? If we preempt a resource from a process, what should be done with that process? How do we ensure that starvation will not occur, guarantee that resources will not always be preempted from the same process? Process, Instruction, Procedure, Function.. Starvation, mutual exclusion, RAG, safe state g Each process in a system has a segment of code, called , in which the process may be changing common variables, updating a table, writing a file.
Critical section, semaphore, race condition, segment table. Dispatcher, LTS, processor, aging. Batch, Time sharing, Real time, None. Parallel, distributed, overlay, spooling l In scheduling algorithm, the process that requests the CPU first is allocated the CPU first. Cache, Register, Secondary, Virtual o In storage management, The user has control over the entire memory space.
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