I've just uploaded my first version of splittar - a small utility that will create tar files for you, but limit the size of each one. I wrote this because I couldn't find anything that would generate tar files of a certain size for me, and splitting one giant tar file isn't acceptable to me because that means in order to recover any data out of the piece, you need all of them assembled back into the original file...Which can mean several tens of gigabytes for me. You can check it out at https://atlee.ca/blog/software/splittar