Split a large file into smaller files and then integrate them to get the original file

To split:

split -b 1G -d bigfile bigfile-part

To join:

cat bigfile-part* > bigfile

To split the file into 1024MBs, using a terminal:

split --bytes=1024m original_filename /destination/path/prefix

To get the original file:

cat /source/path/prefix* > original_filename