Illustrates how the glite WN can be run inside the VirtualBox serivce.

The worker node is stongly connected with the batch processing server. In our infrastructure PBS was deployed as the batch system. PBS consists of two components the server side (usually running on the computing element CE) and a client part running on each WN. The services running on the CE and WN nodesmust be able to communicate. There are three problems with the communication between these nodes:

• The host operating system (Windows) has it's own firewall
• The VirtualBox uses NAT for the guest operating system
• Firewall issues between the batch nodes (usualy located on a private network)

To answer these problems VPN is the easyest solution. The guest machine creates a VPN between the CE and WN, which makes the services possible to communicate with each other.

The gLite WN also requires a passwordless SSH from the WN to the CE node. To achieve this the SSH server on the CE node is configured to accept the WN client by host based authentication through the VPN interface.

These were the modifications which are strictly required in addition to the normal configuration of a WN node.

Modifications on the CE node:

VPN server must be installed