Write a short note on computer security

Security A firewall is a device installed between the internet network of an organization and the rest of Internet. When a computer is connected to Internet, it can create many problems for corporate companies.

Write a short note on computer security

There are presently three methods in which to achieve this: Most commonly, VirtualBox will use large image files on a real hard disk and present them to a guest as a virtual hard disk.

Each such virtual storage device image file, iSCSI target or physical hard disk will need to be connected to the virtual hard disk controller that VirtualBox presents to a virtual machine. This is explained in the next section.

write a short note on computer security

VirtualBox can emulate the five most common types of hard disk controllers typically found in today's PCs: Initially, this interface worked only with hard disks, but was later extended to also support CD-ROM drives and other types of removable media.

In physical PCs, this standard uses flat ribbon parallel cables with 40 or 80 wires. Each such cable can connect two devices to a controller, which have traditionally been called "master" and "slave". Typical PCs had two connectors for such cables; as a result, support for up to four IDE devices was most common.

In VirtualBox, each virtual machine may have one IDE controller enabled, which gives you up to four virtual storage devices that you can attach to the machine. This makes no difference in terms of performance, but if you import a virtual machine from another virtualization product, the operating system in that machine may expect a particular controller type and crash if it isn't found.

Compared to IDE, it supports both much higher speeds and more devices per controller. Also, with physical hardware, devices can be added and removed while the system is running.

Also, this allows you to connect up to 30 virtual hard disks to one machine instead of just three, as with the VirtualBox IDE controller with the DVD drive already attached.

For this reason, starting with version 3. One virtual SATA controller is created by default, and the default disk that is created with a new VM is attached to this controller. After this, the additional controller will appear as a separate PCI device in the virtual machine, and you can add virtual disks to it.

SCSI was standardized as early as as a generic interface for data transfer between all kinds of devices, including storage devices. Today SCSI is still used for connecting hard disks and tape devices, but it has mostly been displaced in commodity hardware.

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It is still in common use in high-performance workstations and servers. After this, the additional controller will appear as a separate PCI device in the virtual machine.

Warning As with the other controller types, a SCSI controller will only be seen by operating systems with device support for it. Windows XP ships with drivers for neither. As opposed to SCSI, however, with physical devices, serial cables are used instead of parallel ones, which simplifies physical device connections.

At this time, up to eight devices can be connected to the SAS controller. The USB mass storage device class is a standard to connect external storage devices like hard disks or flash drives to a host through USB.

All major operating systems support these devices for a long time and ship generic drivers making third-party drivers superfluous. The virtual USB storage controller offered by VirtualBox works different than the other storage controller types: When storage controllers appear as a single PCI device to the guest with multiple disks attached to it, the USB-based storage controller does not appear as virtual storage controller.

Each disk attached to the controller appears as a dedicated USB device to the guest. Operating systems need to support NVMe devices to make use of them. For example Windows 8. In summary, VirtualBox gives you the following categories of virtual storage slots: Given this large choice of storage controllers, you may ask yourself which one to choose.

In general, you should avoid IDE unless it is the only controller supported by your guest.Providing educators and students access to the highest quality practices and resources in reading and language arts instruction. Write short notes of computer based management information system?

information provided to the management for decision making with the help of computer is known as Share to. If you're not familiar with the Oxford Press series of very short introductions to many topics, the Big Data book by Professor Holmes at U Cal, Santa Barbara packs a lot of information into a relatively short book ( pages in paperback).

Perhaps the most well-known computer security threat, a computer virus is a program written to alter the way a computer operates, without the permission or knowledge of the user. A virus replicates and executes itself, usually doing damage to your computer in the process. The Effects of the Spectre and Meltdown Vulnerabilities.

On January 3, the world learned about a series of major security vulnerabilities in modern microprocessors. A computer is a device that can be instructed to carry out sequences of arithmetic or logical operations automatically via computer rutadeltambor.com computers have the ability to follow generalized sets of operations, called programs.

These programs enable computers to perform an .

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