Spanning files across multiple CD and DVD's

Asked by brow96 on 2007-08-13

I need to copy files, in an uncompressed format to CD or DVD's. If the total file size does NOT exceed the capacity of the CD or DVD then everything is ok. If, on the other hand the files exceed these limits? Then data is refused, i.e. put a bigger removalable media in the drive. That would be ok, too, but not many computers can read either DL disks or DVD-RAM disks.

This "spanning" feature is available in many Backup programs. Why is it not available in K3B? Backup programs, in general, will not solve this problem. Access to these files needs to be straight forward, i.e no complicated interface, restore program, etc., etc.

I have to deal with clients, who are NOT very computer literate. They just want the files recovered from a crashed drive or machine. That's all, nothing else. Giving them a complicated interface or some kind of "restore" program, just confuses them, i.e it scares them.

If there is a "spanning" feature in K3B or any other piece of software? I've yet to find it. Nearly every application, for Windows and Linux, supports this feature. Unfortunately support for this stops at "Data" Spanning. If you want to write 60GB of Music or Video to CD or DVD, there is NO PROBLEM. Try writing a 7.51GB "my Documents" directory to a DVD or CD and you'll see what I mean!

I've been around a long time. I've used programs from the DOS world that would fill up a floppy disk and keep telling you to put another one in until all the files were copied to the disks. I've used the same type of program under Windows 3.1x/9.x/W2k/XP/Linux. Unfortunately none of these applications support writing to a CD or DVD.

I'm trying real hard to figure out why this "feature" has been left out!

Hope someone here has an idea!?!


Question information

English Edit question
Ubuntu k3b Edit question
No assignee Edit question
Last query:
Last reply:


   Sorry to hear that you are having some frustrating issues with backing up data. There are numerous ways to achieve your goal. However, the following comment may make it suboptimal from your perspective:

"This "spanning" feature is available in many Backup programs. Why is it not available in K3B? Backup programs, in general, will not solve this problem. Access to these files needs to be straight forward, i.e no complicated interface, restore program, etc., etc."

The most reliable, "doesn't need extra tools" way to do this is to split the file into chucks, and then backup the chunks to your media. The following command would split the file into CD sized chunks (with a little padding for safety):

              split --bytes=649M -d <infile> <prefix>.

The files will be named <prefix>.00 , <prefix>.01 , etc.

When the data needs to be restored, you can use the 'cat' command to append the pieces together again. e.g. cat backup.00 backup.01 > backup

The "tar" command also has a -M switch that allows you to create multi-volume archives. If you use CDRW or DVDRW media with UDF, this should allow you to create multi-volume tar files, and tar should just prompt for the next media, like you said you wanted.

I think, however, that the root of your problem is that K3B isn't a full fledged backup program. It is for creating CDs/DVDs, and the ability to backup is really just a side effect. There are a number of commercial products that support your needs (Arkeia, BRU, etc.), but I am not finding any OSS programs with a quick search. Perhaps looking around on Google or Freshmeat will turn something up.

    Sorry I couldn't be of more help.


brow96 (brow96) said : #2

Thanks Matt:

I'm aware of this solution, and I've used this method many times.

What it doesn't do is give access, by the client, in a straight forward way. What you have to realize is that "I" am not accessing this data, the client is. Their level of experience is what dictates just how complicated a disk I can make for them. If they have to access the command line in any way, then I've failed to give them something that is useful to THEM.

I've sent many a disk to friends with compressed data on it. They have no problems working with these files and the methods that I used to store them. However, an 87 year old Grandmother, has little or no experience with these things, and is NOT going to bother to learn, this late in her life. All she wants is the logs and files from her emails and family pictures that were stored on her old drive.

The only way is to break up the files into segments smaller than the CD or DVD media capacity. This requires a lot of work and is very time consuming. It's too bad when it's a few Gigabytes. But, when you have to do it to 100+ GB's of music, video and documents. It can take days to do this evolution. I know I've done it before.

That's why I'm asking about a "spanning" feature for "Data" CD's and DVD's. It would make my life a whole lot simpler. I can easily sit for and hour or two "feeding" the CD or DVD burner with disks. Rather than spending a few days breaking up the files on a separate HDD and then grouping them so that I don't exceed the capacity of the CD or DVD.

Thank you for your time and effort Matt.


Launchpad Janitor (janitor) said : #3

This question was expired because it remained in the 'Open' state without activity for the last 15 days.

Ben Straton (fanum) said : #4

+1 for this feature. I also looked for a solution, and found this:

I dont see why something similar to this (or exactly this) could not be implemented in k3b.