Artical review on computer file mgmt Essay Example | Topics and Well Written Essays - 500 words

Artical review on computer file mgmt - Essay Example In the block allocation method there are policies in place that determine sequence, locality and so on. When the block of data satisfies the requirement they are allocated the space. The difficulty in this method arises when files are deleted. The original relationships are discarded creating truncations in clusters. The relations need to be completely redone for each new block of data. The authors realize this to be an inefficient use of cpu power and time. The authors suggest that retaining the file layout instead of loosing it after a deletion is a more efficient way to retain block storage. If the file structure no longer has to be recreated each time a file is deleted then a tremendous amount of processor time will be realized. They propose a Storage Slab Allocator or SSA for an improved method of disk space management. Their novel approach appears to have merit as evidenced by the following file management policy. They propose to add a del_list, which tracks any deleted file original layout and a trunc_list, which likewise record any truncated space layout. These are attached to each block Group (BG) for their SSA. They use the binary strategy in the file layout with 1 identified as used and 0 identified as free; they have termed this the â€Å"invalid† bit. Thus the strategy becomes: The total blocks within the sub file layout whose head block number is free are all free. Otherwise, the next level ‘invalid’ need be checked until the last level. Not all the block number but only the head block of the sub file layout need set to be free when blocks are released. (Zhang, et. al., p. 296) They continue to illustrate the concept as a linear but progressive approach that retains the valuable file storage structures while being able to relinquish or delete the data more quickly. Then subsequently allowing new data to be allocated as a â€Å"slab† of information rather