Global Logical Disks

To ensure correct disk access with migrating logical machines, each logical machine maintains its own local logical disk devices. In the DLMS system, each local logical disk has a system-wide, unique global logical disk identifier. The mapping of local logical disks to physical disks is done on two levels:

1. local-to-global mapping: the global logical disk identifier for a local logical disk is acquired.
2. global-to-physical mapping: the physical disk table is used to map a global logical disk to one or more physical disks.

The DLMS manages physical disk access outside of the logical machines in the DLMM layer. Thus, transparency is given and the residual dependency of the machine hosting the accessed hard drive is reduced to I/O (and does not involve any disk mapping).