Q:

Delete 13000 nodes

I have about 13000 nodes to delete in a Drupal 7 site. I have tried the Views Bulk Operations module to delete 500 nodes at a time, but it times out. I can only delete 50 nodes at time. 
How can I delete more than 50 nodes at time?

A:

VBO is the de facto standard for bulk-deleting nodes, there simply isn't a better way to do it.
As VBO processes in batches it only does 1 (or maybe a couple) of nodes at a time. So if you're receiving timeout errors those are related to the deletion of a single node, not to the entire batch operation.
The standard resolution to something like this is to increase the PHP max execution time to compensate.

A:

Install Devel. Then go to admin/config/development/generate/content in D7 and select all content type. Check "Delete All content".
Enter 0 in "How many nodes would you like to generate? "
Click Generate.
That'll delete all nodes.

A:

Use a VBO and execute it from Drush. I used the following method to delete over 1.5million nodes after scale testing.

Create a new view with a page. Set the filters appropriately to display only the type of nodes you'd like to delete. 
Add a new field: "Bulk operations: Content" 
Check the box next to "Delete item" under 'Selected bulk operations'. 
Save the view.
Assuming you know how to use Drush, run this command: (Use a linux 'screen' to run uninterrupted for big datasets)

drush vbo-execute my_view action::views_bulk_operations_delete_item
Where, my_view is the machine name of your view
You can also use drush vbo-list to display all available views and their bulk operations.
The VBO should now run in the shell, giving you feedback as it goes.

