Split

# split -b300M bigfile.zip bigfile.zip.
# ls -al
total 3110156
drwxr-xr-x  2 root root       4096 Sep  6 21:02 .
drwx------ 19 root root       4096 Sep  6 21:01 ..
-rw-r--r--  1 root root 1592381288 Sep  6 21:01 bigfile.zip
-rw-r--r--  1 root root  314572800 Sep  6 21:01 bigfile.zip.aa
-rw-r--r--  1 root root  314572800 Sep  6 21:01 bigfile.zip.ab
-rw-r--r--  1 root root  314572800 Sep  6 21:01 bigfile.zip.ac
-rw-r--r--  1 root root  314572800 Sep  6 21:01 bigfile.zip.ad
-rw-r--r--  1 root root  314572800 Sep  6 21:01 bigfile.zip.ae
-rw-r--r--  1 root root   19517288 Sep  6 21:02 bigfile.zip.af

combine

# cat bigfile.zip.aa bigfile.zip.ab bigfile.zip.ac bigfile.zip.ad \
bigfile.zip.ae bigfile.zip.af > bigfile.zip