There is a PHP file setting on your hosting account that needs to be changed. The quickest resolution is probably contacting your webhost for help.
Yep – PHP had to go version 4 to 5. I did find another export I did a week ago for my test site that was just under 2m and used that. Not sure why the importer stops at 2M. Not good.
Can be bigger
From http://wordpress.org/support/topic/import-large-wordpress-xml-file?replies=6#post-721905
If you use shared hosting services, you may have to ask your host to increase your upload limit.
The maximum size is controlled by two PHP settings: upload_max_filesize, and post_max_size. These are PHP.INI settings, and you may or may not be able to modify them yourself. It depends on your host. So you have to ask them what the correct way to change their value is for their setup. You may need to edit the .htaccess, you may need to add a few ini_set lines to your wp-config.php file, or you may need to edit a PHP.INI file. Can’t say for sure.
