disk space

[Alberto Brivio]

Dear All,

I have a couple of question about file system issues.

I have a WIN XP HOME SP1 and a 20 GB disk FAT32 formatted

Showing disk properties apperars 18 GB used out of 20 GB total space, but if
I add all directory's space I get 10 GB used.

Why there is this big differences ? Could be for filenames too long and /
or too may levels of subdirectories?

And can I convert FAT32 into NTFS without loss of data=



Regards


Alberto Brivio

 

[Ken Blake]

In

Hi, Ken - and Alberto.


The Win2K version of convert.exe usually resulted in 512-byte
clusters, but the WinXP version usually results in the default 4 KB
clusters. ;<)

Sorry, RC, but I believe you're wrong about that. Go to the site
I suggested, http://www.aumha.org/a/ntfscvt.htm for more
information.

 

[GSV Three Minds in a Can]

Hi, Ken - and Alberto.


The Win2K version of convert.exe usually resulted in 512-byte clusters, but
the WinXP version usually results in the default 4 KB clusters. ;<)

Depends who formatted the FAT32 in the first place .. WinXP formats
FAT32 as 4k-aligned, and will convert it with 4k clusters. If someone
else formatted it (Win9x, ME, 2k, etc.) WinXp will convert 'as best it
can', which will result in cluster sizes of 512, 1024, 2048 or 4096
bytes. As you say, Win2k convert =always= goes for the 'safe' (but
lousy) option, 512 bytes.

 

[R. C. White]

Hi, Ken.

Well, as I said, the WinXP version of convert.exe USUALLY results in 4 KB
clusters.

I'm not a techie. I have read some of the technical explanations but,
frankly, don't understand all of them - and can't remember where I found
some of them. ;^}

But here's one. It's from TechNet online at:
New in File Systems
Table 13.1 Enhancements Since Windows 2000
http://www.microsoft.com/technet/tr...prodtechnol/winxppro/reskit/prkc_fil_ziqb.asp

Just one item from that table (Who knows how OE will format it? Guess I'd
better use HTML for this post.):

Variable cluster sizes are now available on volumes converted to NTFS.
The format command in Windows XP Professional now aligns FAT data clusters
at the cluster size boundary. This alignment improves the conversion of FAT
volumes to NTFS because the convert command can now use a variable cluster
size, up to a maximum of 4 kilobytes (KB), for converted volumes, instead of
a fixed 512-byte cluster size as used in Windows 2000.



It doesn't say that it ALWAYS uses 4 KB, but at least it does NOT always use
512-byte clusters, as Win2K usually did. Even in Win2K, according to some
of the articles that I read, a sophisticated techie could do some
machinations to get 4 KB clusters. Not that I could, understand; but some
gurus could.

RC

 

[Ken Blake]

In

Hi, Ken.

Well, as I said, the WinXP version of convert.exe USUALLY results in
4 KB clusters.

I'm not a techie. I have read some of the technical explanations but,
frankly, don't understand all of them - and can't remember where I
found some of them. ;^}

But here's one. It's from TechNet online at:
New in File Systems
Table 13.1 Enhancements Since Windows 2000
http://www.microsoft.com/technet/tr...prodtechnol/winxppro/reskit/prkc_fil_ziqb.asp

Just one item from that table (Who knows how OE will format it?
Guess I'd better use HTML for this post.):

Variable cluster sizes are now available on volumes converted
to NTFS. The format command in Windows XP Professional now aligns FAT
data clusters at the cluster size boundary. This alignment improves
the conversion of FAT volumes to NTFS because the convert command can
now use a variable cluster size, up to a maximum of 4 kilobytes (KB),
for converted volumes, instead of a fixed 512-byte cluster size as
used in Windows 2000.



It doesn't say that it ALWAYS uses 4 KB, but at least it does NOT
always use 512-byte clusters, as Win2K usually did. Even in Win2K,
according to some of the articles that I read, a sophisticated techie
could do some machinations to get 4 KB clusters. Not that I could,
understand; but some gurus could.

Sorry, I don't at all get from that that the convert command
*usually* results in 4K clusters. Nor is that my experience.

--
Ken Blake
Please reply to the newsgroup

In

Hi, Ken - and Alberto.

2. Using the convert command usually results in 512-byte clusters
instead of the default 4K clusters you should have with NTFS.

The Win2K version of convert.exe usually resulted in 512-byte
clusters, but the WinXP version usually results in the

default
4 KB

clusters. ;<)

Sorry, RC, but I believe you're wrong about that. Go to the site
I suggested, http://www.aumha.org/a/ntfscvt.htm for more
information.

--
Ken Blake

In Alberto Brivio <[email protected]> typed

I have a WIN XP HOME SP1 and a 20 GB disk FAT32 formatted

Showing disk properties apperars 18 GB used out of 20 GB total
space, but if I add all directory's space I get 10 GB used.

Why there is this big differences ? Could be for filenames too
long and / or too may levels of subdirectories?


No, it has to do with slack space. Files are allocated disk space
in units called "clusters." With your 20GB FAT32 partition, each
of your clusters is 16K. That means that all files between

1
byte

long and 16384 bytes (16K) long take up 1 cluster, all files
between 16385 bytes and 32768 (32K) bytes use two clusters, and
so on.

So unless a file is exactly a multiple of 16384 bytes long it
wastes the end of the last cluster allocated. That waste is
called "slack." If for example, you create a 500-byte file, it
takes one cluster or 16384 bytes. In Windows the 500 bytes is
called "file size," and the 16384 bytes it actually uses is "size
on disk."

Since almost every file wastes part of one cluster, assuming a
random distribution of file sizes (not exactly correct, but close
enough for this discussion), it can be assumed that the average
waste is half a cluster per file. So total slack is, very
roughly, half your cluster size times the number of files

on
the

drive.

The difference between the two numbers you report 18GB and 10GB
is slack space. 8GB divided by 8192 (half your cluster size)
gives 131,072, which is roughly the number of files you

must
have

on your drive.


And can I convert FAT32 into NTFS without loss of data


Yes. Use the CONVERT command. From a command prompt, type CONVERT
/? to see its help file. However, note two things:

1. Although it's unlikely, it's always possible that something
can go wrong when doing this, and it's prudent to be sure you
have a backup of anything you can't afford to lose.

2. Using the convert command usually results in 512-byte clusters
instead of the default 4K clusters you should have with

NTFS.
And

that implies a performance loss. To deal with this issue, read
http://www.aumha.org/a/ntfscvt.htm
before beginning.