I have a question about file compression.

[Guest]

What are the advantages and disadvantages of compressing one's C drive, I mean, I know it makes the folders take up less space, but are there any problems which come with it? Like certain shortcuts not working? Or like, speed decreasing from having to read compressed files? I think I may want to compress my C drive, but I'm not sure how I'd do it... can anyone help me?

 

[Plato]

What are the advantages and disadvantages of compressing one's C drive, I mean, I know it makes the folders take up less space, but are there any problems which come with it?

Never compress your C: drive.

 

[Carey Frisch [MVP]]

Compression adds overhead to a system because a compressed NTFS file is
decompressed, copied, and then recompressed as a new file even when the file
is copied in the same computer.

Optimizing NTFS Performance
http://www.microsoft.com/resources/...Windows/XP/all/reskit/en-us/prkc_fil_punq.asp

File Compression
http://www.microsoft.com/resources/...Windows/XP/all/reskit/en-us/prkc_fil_oexm.asp

--
Carey Frisch
Microsoft MVP
Windows XP - Shell/User

Be Smart! Protect your PC!
http://www.microsoft.com/security/protect/

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| What are the advantages and disadvantages of compressing one's C drive, I mean, I know it makes the folders
take up less space, but are there any problems which come with it? Like certain shortcuts not working? Or
like, speed decreasing from having to read compressed files? I think I may want to compress my C drive, but
I'm not sure how I'd do it... can anyone help me?

 

[Guest]

There are serious diadvantages to compressing your C: drive
accessing files takes a lot longer as the computer has to
decompress everyfile you compress. Maybe you should look
into removing files or programs no longer needed. Or
invest in a second hard drive. I would not suggest
compressing an entire drive.

-----Original Message-----
What are the advantages and disadvantages of compressing

one's C drive, I mean, I know it makes the folders take up
less space, but are there any problems which come with it?
Like certain shortcuts not working? Or like, speed
decreasing from having to read compressed files? I think I
may want to compress my C drive, but I'm not sure how I'd
do it... can anyone help me?

 

[*Vanguard*]

"Sara" said in news:[email protected]:

What are the advantages and disadvantages of compressing one's C
drive, I mean, I know it makes the folders take up less space, but
are there any problems which come with it? Like certain shortcuts not
working? Or like, speed decreasing from having to read compressed
files? I think I may want to compress my C drive, but I'm not sure
how I'd do it... can anyone help me?

Not much to think of. You compress a file to save space. So then you need to uncompress the file to read from it again. Since you realize that compression takes time then you also realize that decompression also takes time. If a file gets opened a lot then the cumulative delay for decompressing it can become significant. However, if you are saving, say, a .doc file that you might read once a day or is really just stored on disk because you might need it months from now, the one- or rare-time delay in decompressing that one file is probably imperceptible. Opening one data file at a time won't hurt you from the decompression delay. Moving 50,000 files from a compressed folder to a non-compressed folder, well, do it in the morning, go to work, and hope it's done when you get back home. Likewise, compressing a config file or any file that is constantly getting opened and closed will slow down whatever process is using that file if it continually needs to be decompressed and recompressed.




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[Bill Blanton]

Not much to think of. You compress a file to save space. So then you need to
uncompress the file to read from it again. Since you realize that compression
takes time then you also realize that decompression also takes time. If a
file gets opened a lot then the cumulative delay for decompressing it can
become significant. However, if you are saving, say, a .doc file that you
might read once a day or is really just stored on disk because you might need
it months from now, the one- or rare-time delay in decompressing that one file
is probably imperceptible. Opening one data file at a time won't hurt you
from the decompression delay. Moving 50,000 files from a compressed folder to
a non-compressed folder, well, do it in the morning, go to work, and hope it's
done when you get back home. Likewise, compressing a config file or any file
that is constantly getting opened and closed will slow down whatever process
is using that file if it continually needs to be decompressed and
recompressed.

That's not strictly true, and depends on the data being compressed or
decompressed. Given that the hard drive's physical access is the slowest step
in the process, you may actually see a faster "total file" read/write on a
highly compressable file.

Compare a large uncompressed *.doc that uses 10 clusters with the same doc
compressed possibly only needing 5 clusters. Even though the data has to be
run through the compressor or decompressor, this will still be overall faster
than doing the extra 5 cluster physical reads or writes.

OTOH, reading/writing low compression files such as exes or jpgs will probably
suffer some overall performance loss, and may not save any space at all.


Generally, I agree that it would be wise to stay away from compressing a whole
drive. Not just for the extra overhead and possible performance reasons, but
also from a data recovery standpoint.

 

[Alex Nichol]

What are the advantages and disadvantages of compressing one's C drive, I mean, I know it makes the folders take up less space, but are there any problems which come with it?

Do not, repeat *NOT*, compress the entire drive. That will compress the
essential boot files and it will then not boot. If you have an NTFS
drive it can save quite a bit of space to compress *folders* of files
that are not used much. The examples are the $NTUninstal. . . folders
that only get used at all if you decide to uninstall the related hot
fixes; or the ServicePackSourceFiles or System32\dllcache folders -
files that are only used if you are installing new hardware or if file
protection finds an 'in use' copy damaged or missing.

 

[Ken Blake, MVP]

In

"Sara" said in


Not much to think of. You compress a file to save space. So then
you need to uncompress the file to read from it again. Since you
realize that compression takes time then you also realize that
decompression also takes time. If a file gets opened a lot then the
cumulative delay for decompressing it can become significant.

Although it's true that compressing and decompressing files takes
time, it's also true that compressed files are smaller than
uncompressed files, and reading and writing smaller files *saves*
time. Which of the two factors is more significant depends on the
relative speeds of your CPU and drive, but on most modern
computers, there usually isn't a great deal of difference, and
it's close to a wash.

Much more significant, to me, is that when you compress an entire
drive, you're putting all your eggs in one basket. A minor disk
problem, that on an uncompressed drive, might cause the loss of a
single file, can, on a compressed drive, cause the loss of the
entire drive. That's too big a risk to run, in my opinion,
especially on these days of very cheap hard drives; I would just
get a bigger drive instead.

But all this is theoretical anyway, since Windows XP doesn't
provide DriveSpace, or other drive compression software.