1 GB of data on a 700 MB CD-R?

Hi. I’m a newbie to this forum, but not to the systems industry (I’ve been a systems developer for about 25 years). Unfortunately, as much as I read the industry stuff, I just cannot keep up with all the changes, updates, etc. of the system. So this question may turn out to be really basic to many of you:

I have a standard Imation 700mb CD-R written in CDFS format and has several folder names in MS-DOS format (e.g., FINANC~1). I wanted to change the name of the folders for clarity, so I just thought I’d copy the data over to my hard drive, correct the names, then rewrite the data back to a blank CD.

Copied the data to hard drive (no problem). Corrected the names (no problem). But when I started to write the data to a blank CD, I got an error message telling me that there was not enough room on the CD to take the data.

“Huh?” I thought to myself.

I checked the total size of the data on the source CD in CDFS format; it totaled 600MB (100MB of the CD showed as free space). Checked the total space of the copies on my hard drive; they totaled more than 1GB of storage.

“HUH?!” I thought to myself again, but this time with more emphasis.

I checked the sizes of the data again, 2 different ways with 2 different results:
(a) Using Windows Explorer, I highlighted “My Computer” on the left side, then highlighted the Source CD-R on the right side and saw that it had 600MB of data and 100 MB of free space.
(b) Using Windows Explorer, highlighted the CD drive on the left side, then highlighted all the files and directories on the CD (that were shown on the right side) and checked the properties, only to find that it was more than 1GB of space.

“HUH?!” I thought to myself yet again.

I have tried and tried a number of methods to make sense of all this. I’ve tried copying the files different ways using different tools…didn’t make any difference. I created an .ISO of the data on the hard drive, thinking it might compress it down to <700MB; didn’t work. The ISO was over 1GB. (I didn’t create an ISO image from the source CD since I couldn’t change the folder names once it was created).

All my other CD’s that I’ve written have been in CDFS format…no problem. The space requirements for the data I was writing from my hard drive was always the same as the written copy on the CD.

Anyone have any ideas I can pursue about this? What the heck am I missing (besides my marbles). :confused:

TIA for any ideas.

in case it helps:
This is on a Toshiba Satellite laptop running XP w/SP2.

Hi syguy and welcome to the forum.

The CDFS allows for a file to be referrenced in any number of directories. Think of it this way:




The ‘big_file.dat’ file could actually be one file on the CD that is 600MB big. But, since it is referrenced in 3 folders, it will be copied to your hard drive 3 times (requiring 1.8GBs).

Hope this is correct and makes sense.


All you did was rename files. you didn’t modify any of them?

Try to make an ISO image of the CD, and then modify files by extracting fromt he image and inserting them back in, this is really odd otherwise and if not for it being a CD which seems like you made, I would say it is implicit some protection exists on it, perhaps a Illegal TOC.

i dont know what programs you have for cd burning. with nero 6, you can drag the files to the new compilation window and change the file names before burning. hope this helps


[quote=troy512;1924011]i dont know what programs you have for cd burning. with nero 6, you can drag the files to the new compilation window and change the file names before burning. hope this helps


edit//use the original backup disc as the source. copy disc to disc.

Hi [B]syguy[/B], welcome to CDFreaks! :slight_smile:

RichMan explained why this is happening - one or more files are present in multiple folders but only saved once on the CD with multiple references to the same fil(s).

If you want a tool that will let you create ISO images, edit ISO images (inserting, removing and renaming files and folders), and will let you create and handle ISO images with multiple references to the same files, then I suggest you take a look at UltraISO.

UltraISO is Shareware ($30) and I use it regularly for working with ISO images including creating images with multiple references to one file instead of duplicated files. In case you wonder, I use it to consolidate multiple data backups where most files are unchanged between backups.

Things are much easier if you have the right tools for the job.

Richman and DrageMester were right on the money. :smiley: I did some more playing with the source CD and in fact, once I filtered out the pointers and looked only at the actual stored files, the numbers worked out perfectly.

Troy512, I have Nero 6 sitting on an older machine somewhere (now…if I can only find the darn thing!), so if I can locate it, I’ll try it your suggestion.

Thank you all for your insight and suggestions, and DrageMester, I’ll take a look at the UltraISO tool you suggested. It sounds like it could be a great utility to have in my toolbox.

Thanks for a great forum!