What is the difference between "size" and "size on disk" in the "File properties"

Question

In Windows Operating System - if u right click -> properties of any file, it will show u 2 sizes.
Both will differ.
So, What is the difference between "size" and "size on disk" in the "File properties"

Answer 1

Actually these answers are not 100% correct.

SIZE is the actual size of the folder/file when all it's bits are added and counted.

SIZE on disk is the amount of space a file consumes on the disk.
Permit me to explain futher. there is a setting called ALLOCATION UNIT SIZE which can be set when formating a drive. The allocation unit size formats the harddrive so that each allocation unit can store the maximum amount of information to each unit.

Lets say your allocation unit size is set to 4 kilobytes (or 4096 bytes).

Next lets say you wnat to save a file to the harddisk that is 1 kilobyte (1024 bytes) like a shortcut. that information is written to a the uit block. you can only store information from one file on a block so the other 3 kilobytes go unused.

if you want to store a file of 11 kilobytes and each block is assigned 4 kilobytes, then the file will use 2 complete blocks and the other information will use up 3 kilobytes of another block with 1 kilobyte to spare or free with no other file allowed to store information there except that file.

You can see i am right by doing the following.
Right Click any shortcut in Windows and select PROPERTIES and then click on the GENERAL Tab. the SIZE ON DISK will be equal to the ALLOCATION UNIT SIZE set when your harddrive was formated while the actual size of the shortcut will be a few 1 or two kilobytes.

I hope that explains your question.

If your allocation size is 32 kilobyte and your shorcut's for example take only two kilobytes of space the other 30 kilobytes are wasted. In some instance 32 kb allocation is better for performance but it will depend on the size of the drive. If windows formated your drive it most likely picked the best allocation size foer your drive.

Answer 2

Size is the size of the file contents while size-on-disk is how many blocks it needs to store the file. For efficiency reasons, most disks are partitioned into sizeable chunks, usually about 4k (but there are other sizes). That means a file anywhere from 1-4095 bytes will fit in a 4k chunk and will, to the filesystem, take up the entire 4k chunk. Any file from 4096-8191 bytes will take 8k on the disk. And so on and so on...

You can try it. Create a file and put in the text "abc". Create another file and put in the test "abcdef". They will show different sizes but will take the same space on disk.

Note that all of this information does not include the filename. The filename is stored in a special file called a "directory". The directory entry contains the name of the file, the location of the file, and various attributes (access time, creation time, etc...) Shortcuts are files that are links to a different path.

Answer 3

size means the size of the data the file contains

size on disk means size of the data the file contains and the size of all space that is needed to show where it the data begins ,which folder is it in, when was it created and so on...

Answer 4

size = size of the data (actual)

size on disk= size taken by a data on disk which depends on disk u r using thats y some data which take some space one disk take some other space on some other disk like CD or DVD

Answer 5

size on disk is what it is on the hard drive like if its compressed it will be different then the actual size of the file

Answer 6

length isn't something however the truly length of the report. yet length on disk is the scale it has occupied on the disk. we will not keep one little bit of advice on difficult disk. we can keep a minimum of one byte on the disk. even yet it is going to take the fragmented area additionally in attention. So the the disk on length could be the entire fragment area (consisting of length of the report)

Answer 7

Hi, just wanted to mention, I liked this discussion. quite valuable answers

Answer 8

I doubt this is feasible