How do I split a large MySql backup file into multiple files?

Simplest way to split the backup file is to use a software sqldumpsplitter, which allows you to split the db file into multiple db files. Download here

Or else use this terminal command.

split -l 600 ./path/to/source/file.sql ./path/to/dest/file-

Here, 600 is the number of lines you wish to have in your split files. And the two arguments are source and the destination of the files respectively.

NOTE: you must check the split files, you don't split any command.

From How do I split the output from mysqldump into smaller files?

First dump the schema (it surely fits in 2Mb, no?)

mysqldump -d --all-databases

and restore it.

Afterwards dump only the data in separate insert statements, so you can split the files and restore them without having to concatenate them on the remote server

mysqldump --all-databases --extended-insert=FALSE --no-create-info=TRUE

I wrote mysqldumpsplitter (shell script), which splits the databases/tables as instructed in a quick and easy way. See all the possible use cases of how-to extract from mysqldump.

sh mysqldumpsplitter.sh --source mysqldump-file.sql --extract DB --match_str database-name