In order to change this for the products that are already in your catalog runt this query on your database:
UPDATE `cataloginventory_stock_item` SET `is_qty_decimal` = 1;
And rebuild your stock index.
I know...I know ...'don't edit the DB directly'. Well...I do it often because it solves the problems easily, and (I like to think) I know what I'm doing.
For the new added products just set the field Qty Uses Decimals to Yes.
This is going to be unpopular if you've already done a lot of work on your catalog. So - take it with a grain of salt.
In reality you're not really selling a bundle of products that have varying quantities - having 64GB of RAM in a server may equate to 4x 16GB but does your customer have to know or intuit that? It should just be an option in-and-of itself and not have to deal with quantities. It also sounds like there is a relationship between all of the attributes.
So in this case you're really describing a configurable product.
A configurable product is a product that has many variations that all have fixed specifications. Take a tshirt for instance:
- It can come in red, blue, green
- It can come in small, large, xlarge
- It can come in male, female, tanktop varieties
Each of these products is actually a separate product - e.g. a small red tanktop or a large green male tshirt and for each of these you have a finite quantity available. That is to say that you can sell out of the small size but still have an xlarge available in the same color and style.
So I would recommend that you reconfigure your catalog to these specifications. You would have the following configurable attributes on a Virtual Server:
- RAM quantities (2, 4, 8, 16, 32, 64GB)
- CPU quantities (1x, 2x, 4x, 8x, 16x)
- HDD space (100, 250, 500, 1000GB)
And then you would have physical products that represent each of those configurations. E.g. a 100GB 2xCPU server with 16GB RAM.
Magento helps you create these by defining the pivot attributes and then in the parent configurable product creation screen suggesting that it create the products on your behalf. That helps speed some of this up.
This also lets you avoid the situation where you know you won't be able to accomodate a 16CPU/64GB/1TB box - just mark that option out of stock.
When added to the cart this appears as a single line item with a description and they can then change the quantities at-will.
Hope that helps.
Best Answer
I actually found the solution, you CAN do this in the Backend by going to
Note: Product price MUST be over 1 euro/dollar/any currency, or it won't work.