Re: Black and blue colored file names

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C A Upsdell > wrote:

John John (MVP) wrote:

The system decides that one of my files is infrequently used, and compresses it. I then use it every day for the rest of my life. Will it ever get decompressed *back to its original state* without intervention from me? The compression didn't require intervention, after all.


When you open the file the operating system will automatically decompress it so that it can be read and used, once you are done with the file the operating system will automatically compress it again, all of that will happen without intervention from you. There is a bit of an operating system overhead in doing the above, the operating system has to take extra steps when it opens and closes the files. If you do indeed use the file regularly then you can just do as Gerry said and change the compression attribute on the file or on the folder holding the file.


If the file is to be read only, there is no need to re-compress.

The operating system has to decompress the file to read it and regardless of if the file is read-only or not, when the compress attribute is set on the file it will be compressed again after you close it.


I wonder how much overhead truly exists in decompressing files. Yes, more CPU time will be required. OTOH, if the compressed file is much smaller than the decompressed file, the file on the disk will be shorter and therefore disk I/O will be faster.

Yes, there is some overhead in the decompress/re-compress process and this overhead is usually greater than the disk I/O differences. The difference may be negligible on a workstation doing light work but you certainly don't want to compress files on a busy server!

Best practices for NTFS compression in Windows
http://support.microsoft.com/kb/251186/en-us

How To Use File Compression in Windows XP
http://support.microsoft.com/kb/307987/en-us

John
.

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