'size' vs. 'size on disk' ???

[anandk]

in 'windows properties' of a xp folder, the figures for
size, and
size on disk
are different.
what is the difference betwn the 2 ?

eg, my c/windows shows :roll:
size as 4.70 gb but
size on disk as 3.35 gb.

anyone can share !?

[sakumar79]

All the files are stored not in terms of their actual size but in terms of their allocated size... Depending on the partition format (FAT16, FAT32, NTFS), the files are allocated a multiple of certain kb. Therefore, size of a file is different from the size allocated for it on the disk. For eg, NTFS uses multiples of 4kb (If I am not wrong). So, even if the actual file is only 100 bytes (many .ini files are very small), it will occuply 4 kb on the disk... If the file is 4.1kb actual size, it will occupy 8kb...

What is strange though is that the size on disk you have shown is less than actual size... Never seen that before...

Arun

[puja399]

Originally Posted by sakumar79

What is strange though is that the size on disk you have shown is less than actual size... Never seen that before...

Arun

I think its due to NTFS compression.

[QwertyManiac]

Yes its due to the NTFS file system's Compression.

In FAT if u see the size on disk will exceed the actual size. :roll:

[alib_i]

yeah .. it must be NTFS file-system level compression ..

@anandk
do you have NTFS ?
does your system file show some files in blue colour ?
(those blue files are compressed files)

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alibi

[anandk]

thnx 4 d info sakumar. btw, i have specefied the size/size on disks correctly.

thnx puja, quertymaniac.

yes alibi, i have ntfs. and some files do show in blue lettering.

[legolas]

alib_i,

i too hav some blue files, thou i dint intend to do anything to make it so! how do i revert it back? is it automatic? the process of compressing necessary files?

/legolas

[kalpik]

Some system files are automatically compressed via windows.

[vijay_7287]

Originally Posted by legolas

alib_i,

i too hav some blue files, thou i dint intend to do anything to make it so! how do i revert it back? is it automatic? the process of compressing necessary files?

/legolas

it is a system default to show all NTFS compressed file in blue
u can change it in the folder options

[puja399]

Originally Posted by legolas

alib_i,

i too hav some blue files, thou i dint intend to do anything to make it so! how do i revert it back? is it automatic? the process of compressing necessary files?

/legolas

U don't need to revert, NTFS compression is harmless (in fact, good), takes low CPU time, but u can't use NTFS encryption though if they r compressed (u can use 3rd party encryption). U can change option in 'Folder Option' to remove the blue colour, but I think its not necessary.

[alib_i]

legolas,
Leave it as it is ... there's no problem with it.
Windows usually compresses only files which are rarely used.

More reading:
Read Diesel's posts in :: http://forums.aliensoup.com/showthread.php?t=6985

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alibi

[selva1966]

I was also worried about this difference in 'size' when I was choosing avatar. BTW which size is important to be below the 10KB limit.

[alib_i]

I think it should be the actual size of the file.
Because mostly PHP users employ the filesize() function to calculate size of file and this function will always return the actual size in bytes.

Most people (and PHPbb too) dont take the pains to finding the 'size on disk' in these kind of cases.

But if you actually want to find the size of file on disk using PHP then you may take a look at shalless's post in THIS page

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alibi