Figure 1 shows a high-level overview of ALDR. Each POWER server runs one or more guest OSes or LPARsusing the PHYP hypervisor. The AIX LPARs require a small portion of the kernel space memory to be accessed in address-translation-off mode. This region, called RMA (Real Mode Area) is used by OS boot code before translation tables are set up, by the translation-fault handling code during run time, and by a small part of firmware called PFW(Partition FirmWare) that acts as a glue between the kernel and the hypervisor. The POWER architecture also allows RMA to be virtualized by the hypervisor in which case this region is called VRMA. The VIOS LPAR [8] enables the sharing of physical I/O resources across the VIOS-client LPARs within the same managed server. ALDR currently relies on the VIOS to enable quick and efficient suspension and restart of shared physical I/O and network resources.