6. File Systems
CDFS is the CD File System, HPFS is the old High Performance File system used on Windows NT 3.5
and although it provides file permissions, it is not compatible with NTFS. FAT32 is not supported
by NT. FAT can support long file names up to 255 characters with multiple spaces and periods. Names
preserve case but are not case sensitive. FAT can use drives up to 4Gb and is most efficient for
drives less than 400Mb.
NTFS can be up to 16 Exabytes but not less than 50Mb due to the overhead. NTFS supports
security on a per file basis, bad-cluster remapping, file compression, Macintosh file support
using Services for Macintosh although Macintosh computers have a maximum partition size of
2Gb. NTFS supports POSIX 1.0 that means that file names ARE case-sensitive. Floppy disks cannot
be formatted with NTFS. Recoverability is designed into NTFS so disk repair utilities are
not required. Defragmentation is less frequently required because 20% of the disk space
for a particular file is taken up in anticipation of growth.
For one way conversion of a FAT system to an NTFS system use convert drive: /fs:ntfs.
When working with file systems that use the 8.3 file naming convention, make sure that if
you are using long filenames, the first 6 charaters are unique for each file since the
8.3 file system changes the name to XXXXXX~3.YYY where the tile and the number represent
the extra characters.
Compression is automatic on NTFS partitions but introduces performance degradation. Compression
is not supported on NTFS partitions with cluster sizes greater than 4 Kb.
The compress attribute for a file means that it is compressed whereas the compress attribute
for a folder means that any files place in that folder will be compressed. For a folder the compress
attribute only applies to that folder and not the subfolders!
The following switches are available for Compact.exe:
- /c - compresses files and directories (plus future files)
- /u - uncompresses files and directories
- /s - completes the operation on the files in the directory
- /a - displays files with system and hidden attributes
- /i - continues the operation even after errors have occurred.
- /f - Forces compression on all files even those already compressed, good for when the system
crashes during a compression.
- /q - reports just the summary information
It is not possible to compress NTLDR or the Pagefile.sys.
When copying a compressed file, the file inherits the compression attribute of the target folder.
Moving a file within an NTFS partition means that the file retains its compression attribute
regardless of the folder attributes. Moving between any NTFS partition requires the delete and copy
operations so the compression attribute is inherited from the target folder. The only time a folder
and compressed files appear in blue is when the folder has the compressed attribute set.