I have a pretty big file (more than 20GB) and I'd like to split it into smaller ones, like multiple files of 2GB.

One thing is I have to split before a specific line:

I'm using Python, but if there another solution in shell for example, I'm up for it.

This is how the big file looks like:

`bigfile.txt` (20GB)

```
Recno:: 0
some data...

Recno:: 1
some data...

Recno:: 2
some data...

Recno:: 3
some data...

Recno:: 4
some data...

Recno:: 5
some data...

Recno:: x
some more data...

```

This is what I want:

`file1.txt` (2 GB +/-)

```
Recno::0
some data...

Recno:: 1
some data...

```

`file2.txt` (2GB +/-)

```
Recno:: 2
some data...

Recno:: 4
some data...

Recno:: 5
some data...

```

And so on, and so on...

Thanks !