Are virtual hard disk defragment tools needed?
A file system, generically speaking, works by having an index of files –the Master File Table in NTFS , a Windows file system, for example — that lists all the files it contains. Each of those files is stored in one or more disk clusters, which are each a collection of segments, or sectors, of the physical medium. The index includes basic attributes of a file, such as the name and time stamps, and a listing of all clusters allocated to the file. Ideally the clusters for a file will be allocated sequentially to minimize the amount of repositioning of the drive heads(s) as the platters, the physical components that store data, are read. As a drive is filled, or a file is appended and modified, the clusters assigned will be increasingly non-contiguous, which will degrade performance . Fragmentation, operationally, can cause slow disk access times. Although the analogy is not perfect, it is reasonable to compare this process to the spiraled line of a record: You want the data to be all t
