Please describe the procedure that a cloud infrastructure carries out to run an application.

(1)  Retrieve the user input from the front-end.

(2)  Retrieve the disk image of a VM (Virtual Machine) from a repository.

(3)  Locate a system and requests the VMM (Virtual Machine Monitor) running on that system to setup a VM.

(4)  Invoke the Dynamic Host Configuration Protocol (DHCP) and the IP bridging software to set up MAC and IP addresses for the VM.

It implements a distributed storage system, the analog of Amazons S3 system, called Walrus. The procedure to construct a virtual machine is based on the generic one described in :

• the euca2ools front-end is used to request a VM;

• the VM disk image is transferred to a compute node;

• this disk image is modified for use by the VMM on the compute node;

• the compute node sets up network bridging to provide a virtual NIC with a virtual MAC address .

•in the head node the DHCP is set up with the MAC/IP pair;

• VMM activates the VM;

• the user can now ssh  directly into the VM.