is only visible if the device driver is loaded and the compressed drive is mounted. A boot disk, for example, might not contain the driver. (This was not normally an issue for solutions that came bundled with the operation systems unless booting foreign operating systems, as system utilities like SYS were modified to copy the compression drivers to boot disks by default, and the corresponding operation systems would also fall back to look for them on drives other than the boot disk if they couldn't be found there.) Uninstallation was problematic if the expanded size of data on the compressed disk was larger than the normal disk capacity. Users did not always realize that the large file on the host drive contained the compressed drive. While it was usually "hidden" by default, users who did find the large file curious or suspicious were able to delete it. This would normally result in data loss. See also RAM compression Data compression Disk fragmentation Executable compression Self-extracting archive cramfs e2compr SquashFS MDFAT (DoubleSpace) BitFAT (DoubleSpace) MDBPB (DoubleSpace) Notes References External links ff. Compression Compression Utility software types Compression file systems