AdminXP.com: Compressing under Windows 2000

Compressing under Windows 2000

The compression can be used in the NTFS file system only, in another systems you have to use compression programs designed for creating compression archives, or you can utilize the compressions made by other producers (it was Stacker, Double Space and Drive Space for DOS; for Windows NT/2000 I do not know any product, I cannot also see a reason why should it exist - it would have to be much more better as regards properties than the compression implemented inside the system).
Compressing and decompressing is being carried out real-time - Compared to the common compression programs it is not necessary first to compress or decompress the data using compression archives and programs.
To set up the compression just select or remove the settings of compression attribute for chosen objects. If you do not set up marking of the compressed files or you do not check the compression attribute you will not distinguish the compressed from the extracted files.
The compression is not recommended for frequently read data. It is also not recommended to use the compression for already compressed archives (*.zip, *.rar, *.ace....), system files (the system doesn't allow you to compress the most important ones), and files using compression algorithms (MPEG2 movies, *.MP3 audio files, *.jpg images). The optimal solution is to use the compression for common user data - text documents, tables (sheets), ...

Enable or disable file compression

Choose an object that you want to set up ciphering (coding) for (a file, a folder or several marked objects)
Display the local menu for the marked objects (using the right mouse button) and choose "Properties"

In "General" choose "Advanced..." - Check or uncheck this checkbox: "Compress contents to save disk space"

If exist folder in the selected objects can choose, if the compress will be applied to subdirectories and files, too. - "Apply changes to this folder only" or "Apply changes to this folder, subfolders and files". Option is not displayed at files.

You can also work with the file compression by help of the command line - "compact" command (see compact /?)
To decompress the distribution files (*.cab) use expand command.

Easy distinguishing of compressed files from the others

To distinguish the compressed files better you can use marking. This you can make in the "Folder Options" menu in Control Panels.

In "View" pick "Display compressed files and folders with alternate color".

Result - the compressed files will be marked blue.

Limitations

The compression cannot be used in case of disks formatted with clusters larger than 4K. The default disk formatting is made using an initial cluster size, this value differs according to the size of the partition (the default setting is that the system formats 512b - 4kB clusters, but you can also set up a higher value, the size of a cluster you can find by help of "chkdsk" command). Potential initial cluster size larger than 4kB is 8kb in partitions larger than 4GB, but Windows NT 4 and 2000 format all partition sizes larger than 2GB with 4kB clusters (thanks to compression and more advantageous using of smallish clusters).
Ciphering cannot be used together with compression.
In case of more loaded servers consider if you will preference the performance or saving of the space on the disks, because the frequent processing (accessing to) of files utilizing compression causes higher load of the processor.

Working with compressed files and folders

The rules are similar to the rules for permissions.
When you copy a file to the folder that uses compression the file will also take the compression attribute from the parent folder - it will be compressed.
When you move the file to the folder that uses compression the file will keep the compression attribute unchanged.
When you open and save a file the compression attribute will not change (the compressed file will be temporarily decompressed and after its saving will be compressed again). This rule will not be valid in case you save the file into another folder or under a different name.
When you move or copy the file into a partition that is not NTFS it will be decompressed and the compression attribute canceled.
When you move or copy the file from NTFS partition onto another NTFS partition the compression attribute will be taken from the distant (target) parent folder.