Comparing 'Size on Disk' of CF and Hard Drive at DVinfo.net

Steve Kalle · April 17th, 2011, 05:45 PM

After copying files from the CF card to my raid array, I always check the properties of the Size and Size on Disk to make sure the data copied correctly. However, I have noticed that the 'Size on Disk' is different between the CF card and hard drive while the 'Size' is identical.

I just copied some files and here is the "Size on Disk" as shown in Windows 7 Explorer:
CF card = 6,507,970,560 bytes
raid array= 6,507,913,216 bytes

Here is the "Size" as shown in Win 7 Explorer:
CF card = 6,507,893,276 bytes
Raid array= 6,507,893,276 bytes

Is this normal or should I be worried?

Dan Keaton · April 17th, 2011, 06:26 PM

Dear Steve,

There is no need to worry, and I feel that you files are ok.

The Size on Disk and File Size parameters can be different due to "Cluster Size".

The File Size is what must match exactly.

If the "Cluster Size" between the two devices are different then under most circumstances the Size on Disk values will be different.

Please call me if you wish.

Andy Mangrum · April 18th, 2011, 03:20 PM

Also To add to what Dan had Mentioned this depends greatly on your OS, and the Format of your Raid.

MAC OS Snow Leopard uses HFS file system which shows file sizes and Drive available much differently from a Fat 32, but Windows XP and Windows 7 are Typically NTFS by default, which will very slightly form your CF card which is Fat 32.

Best Regards

Steve Kalle · May 11th, 2011, 11:37 PM

Should I be worried that my 'Size on Disk' is identical but the 'Size' is slightly off? This is coming from SxS cards and the only things different in actual size are the 'CUEUP.XML' and 'MEDIAPRO.XML' files in the BPAV folder.

Dan Keaton · May 12th, 2011, 06:21 AM

Dear Steve,

Unless you are having a problem, I would not worrry about how the sizes are reported.

The "Cluster Size" on the CompactFlash card or SxS card can be different than the "Cluster Size" on a disk.

Thus, if the computer is reporting the size in "full clusters" and not the actual size of the file, then there will be a discrepancy.

Robin Probyn · May 12th, 2011, 08:15 PM

Quote:

Originally Posted by Steve Kalle

Should I be worried that my 'Size on Disk' is identical but the 'Size' is slightly off? This is coming from SxS cards and the only things different in actual size are the 'CUEUP.XML' and 'MEDIAPRO.XML' files in the BPAV folder.

Hi Steve

I share your pain.. worry etc.. then I bought shotputpro.. best $99 you,ll spend.. very easy and you can sleep at night..

April 17th, 2011, 05:45 PM	#1
Steve Kalle Trustee Join Date: Aug 2009 Location: Chicago, IL Posts: 1,554	Comparing 'Size on Disk' of CF and Hard Drive After copying files from the CF card to my raid array, I always check the properties of the Size and Size on Disk to make sure the data copied correctly. However, I have noticed that the 'Size on Disk' is different between the CF card and hard drive while the 'Size' is identical. I just copied some files and here is the "Size on Disk" as shown in Windows 7 Explorer: CF card = 6,507,970,560 bytes raid array= 6,507,913,216 bytes Here is the "Size" as shown in Win 7 Explorer: CF card = 6,507,893,276 bytes Raid array= 6,507,893,276 bytes Is this normal or should I be worried?

April 17th, 2011, 06:26 PM	#2
Dan Keaton Inner Circle Join Date: Dec 2002 Location: Augusta Georgia Posts: 5,421	Re: Comparing 'Size on Disk' of CF and Hard Drive Dear Steve, There is no need to worry, and I feel that you files are ok. The Size on Disk and File Size parameters can be different due to "Cluster Size". The File Size is what must match exactly. If the "Cluster Size" between the two devices are different then under most circumstances the Size on Disk values will be different. Please call me if you wish. __________________ Dan Keaton Augusta Georgia

April 18th, 2011, 03:20 PM	#3
Andy Mangrum Sponsor: Convergent Design Join Date: Jul 2010 Location: Colorado Springs Colorado Posts: 166	Re: Comparing 'Size on Disk' of CF and Hard Drive Also To add to what Dan had Mentioned this depends greatly on your OS, and the Format of your Raid. MAC OS Snow Leopard uses HFS file system which shows file sizes and Drive available much differently from a Fat 32, but Windows XP and Windows 7 are Typically NTFS by default, which will very slightly form your CF card which is Fat 32. Best Regards __________________ Andy Mangrum, Tech Support Convergent Design, Inc

May 11th, 2011, 11:37 PM	#4
Steve Kalle Trustee Join Date: Aug 2009 Location: Chicago, IL Posts: 1,554	Re: Comparing 'Size on Disk' of CF and Hard Drive Should I be worried that my 'Size on Disk' is identical but the 'Size' is slightly off? This is coming from SxS cards and the only things different in actual size are the 'CUEUP.XML' and 'MEDIAPRO.XML' files in the BPAV folder.

May 12th, 2011, 06:21 AM	#5
Dan Keaton Inner Circle Join Date: Dec 2002 Location: Augusta Georgia Posts: 5,421	Re: Comparing 'Size on Disk' of CF and Hard Drive Dear Steve, Unless you are having a problem, I would not worrry about how the sizes are reported. The "Cluster Size" on the CompactFlash card or SxS card can be different than the "Cluster Size" on a disk. Thus, if the computer is reporting the size in "full clusters" and not the actual size of the file, then there will be a discrepancy. __________________ Dan Keaton Augusta Georgia