Slack space

     

      Slack space file slack is space is already in use by the file, but the space is used, is not spent entirely for storing data. resulting in slack space. or an area between the end of a file and end of the last cluster or sector used by the file in question. Area is an area that will not be used again to store the information there, so the area is "wasted" useless.
      Slack space is common in file systems that use a large cluster size, while the file system that uses a small cluster size can organize the storage media more effectively and efficiently.Amount of wasted disk space can be thought is estimated by multiplying the number of files (including the number of directories) with half the size of a cluster.

     For example, a personal computer 500 which stores the file in a file system that uses a cluster size of 4 kilobytes will have approximately 500 x 2 KB = 1000 KB. On a large file server, slack space and even reached the size of tens of gigabytes.
     The more boxes are used, will cause the longer it takes the hard drive to store or read data. (read / write). The ends will slow hard drive performance. However, the larger the box that is used (not much), the greater the allocation unit size we choose, the greater the likelihood of wasting your hard disk and slack space.
There are several ways that can be taken to eliminate the slack space, namely:

a. Do the formatting of the drive in question with a smaller cluster.
b. Using a file system that supports features like ReiserFS tail packing.
c. compression

-  Drive compression: Compression of the drive to reduce slack space because of all the files stored in a compressed volume file.

- File Compression: Compression of the files is to reduce the use of drive space, but does not eliminate the slack. Such applications WinZip, WinRAR, 7-Zip, tar-czf, an example of the many applications that can be used for this method.