Break a large file into smaller pieces

You can use split and cat.

For example something like

$ split --bytes 500M --numeric-suffixes --suffix-length=3 foo foo.

(where the input filename is foo and the last argument is the output prefix). This will create files like foo.000 foo.001 ...

The same command with short options:

$ split -b 100k -d -a 3 foo foo

You can also specify "--line-bytes" if you wish it to split on line boundaries instead of just exact number of bytes.

For re-assembling the generated pieces again you can use e.g.:

$ cat foo.* > foo_2

(assuming that the shell sorts the results of shell globbing - and the number of parts does not exceed the system dependent limit of arguments)

You can compare the result via:

$ cmp foo foo_2
$ echo $?

(which should output 0)

Alternatively, you can use a combination of find/sort/xargs to re-assemble the pieces:

$ find -maxdepth 1 -type f -name 'foo.*'  | sort | xargs cat > foo_3

You can also do this with Archive Manager if you prefer a GUI. Look under 'Save->Other Options->Split into volumes of'.