Unit 7 AssignmentIT332 " Principles of Information Systems A, Lecture notes of Accounting

Download Unit 7 AssignmentIT332 " Principles of Information Systems A and more Lecture notes Accounting in PDF only on Docsity! Unit 7 Assignment IT332 – Principles of Information Systems Architecture Purdue Global University Introduction When it comes to physical secondary storages of computing systems, there are several different types of mediums available. Some of these types of mediums are: DVD, Flash drive, Hard Disk, and tapes. Each type of medium has a different file allocation method and different size constraints as well. Below will discuss the different types of mediums, fragmentation- defragmentation, and how to fix any issues with space and fragmentations. Various Allocations and Storage Devices The first type of allocation is the contiguous allocation, which is the file allocation where the data stored to the disk is occupied on continual blocks of the disk. When it comes to file recovery and retrieval, it is straightforward because the file manager can request a single multiblock read and can read the file in a single pass. However, when files are deleted, they tend to leave gaps in the storage medium. Random access is supported very well by this type of file allocation; however, it cannot handle growing files well, which can make the file sizing changes difficult. Non-contiguous allocation is the opposite of contiguous because data is written to random or various disk spaces because there is not enough space in a single area. This allows the allocation to do what contiguous cannot, which is allow file size to grow if needed over time. The biggest advantage of non-contiguous allocation is that it does not waste disk space and flexibility. This type of file allocation does not really support fragmentation and it utilizes virtual memory allocation. Paging, which is where the memory is divided into fixed size blocks called frames, the size in the power of 2 which can range from 512-8192 bytes. Tape allocation can be called sequential because the user must start at the beginning and rolling through the tape until you find the data they desire. Tapes advantage is that they have a