Run this in terminal
7z a -t7z -v700m -mx0 -r archive_name.7z /source/dir
а - add files or directory to archive;
-t7z - use 7z compression method;
-v700m - split archive into parts of 700 mb;
-mx0 - use zero compression, if you need compression set a number from 1 to 9, where 9 - ultra compression;
-r - recursively (if you want to compress directory).