The article reports that the best way to solve the data storage problem is with a file compressor such as gzip or bzip2. But neither supports random access within a compressed file. Because a forensic tool requires random access in the same manner that a file system requires random access to a physical disk, disk images compressed with a file compressor have be decompressed before they can be used. A second problem with raw images is the recording of metadata. Because a raw image is a sector-for-sector copy of a target drive, there is no place to store additional information in the file. The file format used by a popular EnCase forensic tool overcomes many of the problems inherent with raw images. It stores a disk image as a series of unique compressed pages. Each page can be individually retrieved and decompressed in the computer's memory as needed. It allows random access to the contents of the image file. The EnCase format also has the ability to store metadata such as a case number and an investigator.