I have a php script to backup automatically cPanel and upload the .tar.gz concurrently to an FTP server.
The script works fine.
The script requests the file then starts the ftp transfer and when the upload is complete it send also a confirmation email.
The only problem is that even if the backup is, for example, of 1GB the uploaded file is only of 170mb.
It seems it's not able to upload large files. Infact with a small backup (for example 16mb or 20mb) it's all working fine.
You can see the complete file here http://pastie.org/949680