1. A system for implementing storage for a virtualization environment, comprising: a plurality of nodes implementing a virtualization environment, the plurality of nodes comprising at least a first node and a second node, the second node being different from the first node, and at least the first node and the second node including a respective service virtual machine; a plurality of storage devices that are accessed by virtual machines in the virtualization environment, the plurality of storage devices comprising a first storage device tier and a second storage device tier, the first storage device tier comprising local storage devices that are locally attached to respective nodes of the plurality of nodes comprising at least a first local storage device on the first node and a second local storage device on the second node, the second storage device tier comprising network attached storage devices that are accessed through a network, the first storage device tier and the second storage device tier being part of a global storage pool, and the global storage pool being managed by the respective service virtual machines as a global resource pool; and at least some of the service virtual machines of the respective nodes exposes one or more virtual disks to the virtual machines, at least one of the one or more virtual disks are structured from both the first local storage device on the first node and the second local storage device on the second node and the networked attached storage devices in the global storage pool.