Windows 7 Forums
Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.


Windows 7: Different in File Size & Size on Disk


07 Apr 2010   #1

Windows 7 Build 7600
 
 
Different in File Size & Size on Disk

I'm transferring files, from external hard disk to an another external hard disk...
from a non-external powered to an external powered one...

I'm using cut & paste...

Suddenly, blackout happens...

There'll be data writing failure...

So I checked some of my files(mostly in .iso)... Some of them have very big difference between Files Size & Size on Disk (around 4 GB)...

So, I tried to open it... Nothing happen...

Does this big difference can make anything goes wrong?


My System SpecsSystem Spec
.

07 Apr 2010   #2

Windows 2000 5.0 Build 2195
 
 

Are you talking about this?


Attached Images
 
My System SpecsSystem Spec
07 Apr 2010   #3

Windows 7 Build 7600
 
 

Yup... but in your picture, the difference in not too big... but what happen to me is there value difference is about 4GB
My System SpecsSystem Spec
.


07 Apr 2010   #4
ryo

 
 

Quote   Quote: Originally Posted by iUnique View Post
Yup... but in your picture, the difference in not too big... but what happen to me is there value difference is about 4GB
lol...did you use winzip or winrar??
My System SpecsSystem Spec
07 Apr 2010   #5

Windows 7 Build 7600
 
 

use PowerISO of course...
My System SpecsSystem Spec
07 Apr 2010   #6

Windows 2000 5.0 Build 2195
 
 

EDIT: Considering the power outage, try doing a chkdsk /f and see if it find errors, else you'll have to copy the files all over again.

-Original post by me:
Two possibilities: Compression using the default windows .zip interface and sector size. I would go with the latter. It's like this:

Compression is fairly easy to explain. "Size" dictates what the actual size is, and the "size on disk" dictates how much space it is occupying the hard disk after being squished in to a very small size.

Sectors are a bit more complicated. Your hard drive is divided in to many, many things. The smallest and most important are the sectors. Think of sectors as honeycombs in a bee's hive. They combine together to form an actual hive of honey.

Now, Windows 7 has a default sector size of 4KB. That means that for every block of data, it divides it into a 4KB pieces. Now if you have a 6KB file, the first 4KB will occupy sector 1. The next 2KB will occupy sector 2. You cannot add another file on sector 2 since it is already occupied by a file. Considering that, file 1 is actually occupying 8KB even though it is only 6KB.

To give you an example, I'll show you a screenshot of my PC. My sector size is at 32KB (the bigger, the better in performance :P)


See how even if it's 1 byte it takes up 32KB? It's because of my sector size.


That's a loss of 32,767 bytes. Of course, the effect stacks up. Now see what happens when I copy that file 237 times.



Hopefully that should give you a basic understaning on why there's a big difference on "Size" and "Size on disk".
My System SpecsSystem Spec
07 Apr 2010   #7

Windows 8.1 Pro (x64)
 
 

Durning the copy process, Windows probably made sparse files to pre-allocate large block for the file to be written to. Which might accound for the difference.
My System SpecsSystem Spec
07 Apr 2010   #8

XP Pro SP3 X86 / Win7 Pro X86
 
 

Quote   Quote: Originally Posted by iUnique View Post
I'm transferring files, from external hard disk to an another external hard disk...
from a non-external powered to an external powered one...

I'm using cut & paste...

Suddenly, blackout happens...

There'll be data writing failure...

So I checked some of my files(mostly in .iso)... Some of them have very big difference between Files Size & Size on Disk (around 4 GB)...

So, I tried to open it... Nothing happen...

Does this big difference can make anything goes wrong?


You had a power failure...

The file is incomplete on your destination disk and yes the size difference matters *A LOT*. What you should do is delete the incomplete file and copy it over again.
My System SpecsSystem Spec
07 Apr 2010   #9

Windows 7 Build 7600
 
 

Quote:
You had a power failure...

The file is incomplete on your destination disk and yes the size difference matters *A LOT*. What you should do is delete the incomplete file and copy it over again.
But the prob is, I was moving the file, not copying the file... when I checked back the original hard drive, the file is gone.. but it present in the destination hard drive... have same file size (as what I have remembered)... But I'm getting suspicious about the file size & size on disk... By the way, the file is .iso, when I opened it with PowerISO, I get no error message... It means that there's no prob at all, am I right?

So, the file is actually normal, right?
My System SpecsSystem Spec
08 Apr 2010   #10
ryo

 
 

why you not try use other...dont use powerISO..

compare it.
My System SpecsSystem Spec
Reply

 Different in File Size & Size on Disk




Thread Tools




Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd

All times are GMT -5. The time now is 04:22 AM.
Twitter Facebook Google+



Windows 7 Forums

Seven Forums Android App Seven Forums IOS App
  

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33