**7.5 Clouds and virtualization**

Among the new technologies, the Clouds is the right buzzword now and the virtualization of resources comes along. The virtualization of WLCG sites started prior to the first LHC collisions and has gone quite far. It helps improving system management, provision of services on demand, can make use of resources more effective and efficient. Virtualization also enables to make use of industrial and commercial solutions.

But, no matter what the current technologies advertise, the LHC community will always use a Grid because the scientists need to collaborate and share resources. No matter what technologies are used underneath the Grid, the collaborative sharing of resources and the network of trust and all the security infrastructure developed on the way of building the WLCG is of enormous value, not only to WLCG community but to e-science in general. It allows people to collaborate across the infrastructures.

Fig. 26. Schema of StratusLab IaaS Cloud interoperability with a Grid

The basic operations like distributed data management, the high data throughput and the remote job submission can probably be more cloud-like. There is a great interest among people to use commercial Clouds resources, especially when the experiments see their resources becoming full.

So, can we use Amazon or Google to do processing of data from LHC? The point is, one cannot be sure what the level of services will be and what the IN/OUT bandwidth will be. This can in principle be negotiated with these companies and may bring some level of agreement. That in principle is doable.
