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- Fragmentation within individual files and their metadata.
- Free space fragmentation, making it increasingly difficult to lay out new files contiguously.
- The decrease of locality of reference between separate, but related files.
Wiki User
∙ 13y ago
Wiki User
∙ 12y agoComputer memory works like this: a hard disk etc. is devided up into little packets. Let's say that file one takes up one packet, file two takes up two, and file three takes up three. The disk could then be diagrammed like this: 1-2-2-3-3-3. Then, you delete file two and install file four, which takes up four spaces. A computer always tries to keep files together. The disk can now thus be diagrammed like this: 1-4-4-3-3-3-4-4. This means that to access the second half of file four the computer has to cross all of file three, which makes it slower. That is fragmentation.
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Definition of internal fragmentation and external fragmentation?
External Fragmentation: External Fragmentation happens when a dynamic memory allocation algorithm allocates some memory and a small piece is left over that cannot be effectively used. If too much external fragmentation occurs, the amount of usable memory is drastically reduced. Total memory space exists to satisfy a request, but it is not contiguous. Internal Fragmentation: Internal fragmentation is the space wasted inside of allocated memory blocks because of restriction on the allowed sizes of allocated blocks. Allocated memory may be slightly larger than requested memory; this size difference is memory internal to a partition, but not being used
What is fragmentation in OS?
fragmentation is as a process which are loaded or removed from memory. the free memory space is broken into Little pieces, such types of pieces may or may not be of any use to be allocated individually to any process. this may give rise to term memory waste or fragmentation.
Difference between internal fragmentation and external fragmentation in operating system?
Fragmentation occurs in a dynamic memory allocation system when many of the free blocks are too small to satisfy any request. External Fragmentation: External Fragmentation happens when a dynamic memory allocation algorithm allocates some memory and a small piece is left over that cannot be effectively used. If too much external fragmentation occurs, the amount of usable memory is drastically reduced. Total memory space exists to satisfy a request, but it is not contiguous. Internal Fragmentation: Internal fragmentation is the space wasted inside of allocated memory blocks because of restriction on the allowed sizes of allocated blocks. Allocated memory may be slightly larger than requested memory; this size difference is memory internal to a partition, but not being used
Is relocatable Dynamic Memory external or internal fragmentation?
external fragmentation
WHAT IS SINGLE USER CONTIGUOS SCHEME?
Single user contiguous scheme is a memory allocation technique where a single block of contiguous memory is allocated to a process. This means that the entire memory space needed by a process must be available in a single block without any breaks or fragmentation. It simplifies memory management but can lead to wastage of memory due to fragmentation.
Compare Contiguous memory allocation with internal fragmentation?
in early, computer system has contiguous memory allocation,each process is allocated in a single contiguous(together) memory!!(allocating into memory addresses one by one,)it has tackled memory fragmentation(both internal and external). not allocating for a fixed size memory block.so no internal fragmentation, allocating contiguously ,so no external fragmentation!!!
What are the two types of fragmentation Illustrate them with block diagrams?
Ans) In computer storage, fragmentation is a phenomenon in which storage space is used inefficiently, reducing capacity and often performance. Fragmentation leads to storage space being "wasted", and the term also refers to the wasted space itself.There are three different but related forms of fragmentation: external fragmentation, internal fragmentation, and data fragmentation, which can be present in isolation or conjunction. Fragmentation is often accepted in return for improvements in speed or simplicity.Internal fragmentation: Due to the rules governing memory allocation, more computer memory is sometimes allocated than is needed. For example, memory can only be provided to programs in chunks divisible by 4, 8 or 16, and as a result if a program requests perhaps 23 bytes, it will actually get a chunk of 24. When this happens, the excess memory goes to waste. In this scenario, the unusable memory is contained within an allocated region, and is thus termed internal fragmentation. Slack space is a very important source of evidence in computer forensic investigation.External fragmentationExternal fragmentation arises when free memory is separated into small blocks and is interspersed by allocated memory. It is a weakness of certain storage allocation algorithms, when they fail to order memory used by programs efficiently. The result is that, although free storage is available, it is effectively unusable because it is divided into pieces that are too small individually to satisfy the demands of the application. The term "external" refers to the fact that the unusable storage is outside the allocated regions. External fragmentation also occurs in file systems as many files of different sizes are created, change size, and are deleted. The effect is even worse if a file which is divided into many small pieces is deleted, because this leaves similarly small regions of free spaces.0x00000x10000x20000x30000x40000x5000CommentsStart with all memory available for allocation.ABCAllocated three blocks A, B, and C, of size 0x1000.ACFreed block B. Notice that the memory that B used cannot be included for an allocation larger than B's size.
What is solution of external fragmentation?
External fragmentation is solved by any three methods:- 1.compaction:- attacks the problem of external fragmentation by moving all the allocated memory blocks into single unit by combining all free memory holes. 2.garbage collection:- it collects all the memory which is inaccessible and return them as a free memory. 3.paging:-breaking up physical memory into fixed size blocks and than filling these blocks by logical memory of same size.
What is the difference between external and internal fragmentation?
Fragmentation occurs in a dynamic memory allocation system when many of the free blocks are too small to satisfy any request.External Fragmentation: External Fragmentation happens when a dynamic memory allocation algorithm allocates some memory and a small piece is left over that cannot be effectively used. If too much external fragmentation occurs, the amount of usable memory is drastically reduced. Total memory space exists to satisfy a request, but it is not contiguous.Internal Fragmentation: Internal fragmentation is the space wasted inside of allocated memory blocks because of restriction on the allowed sizes of allocated blocks. Allocated memory may be slightly larger than requested memory; this size difference is memory internal to a partition, but not being usedAnother Definition:Internal Fragmentation is the area in a region or a page that is not used by the job occupying that region or page. This space is unavailable for use by the system until that job is finished and the page or region is released.
Why paging is used?
Paging is solution to external fragmentation problem whichis to permit the logical address space of a process to benoncontiguous, thus allowing a process to be allocatingphysical memory wherever the latter is available.
Why paging used?
Paging is solution to external fragmentation problem whichis to permit the logical address space of a process to benoncontiguous, thus allowing a process to be allocatingphysical memory wherever the latter is available.
Does a paged memory management system have the fragmentation problem at process image level?
No, not at all
