DLPAR enables memory, CPU capacity, and I/O interfaces to be moved nondisruptively between LPARs within the same server.
The Linux kernel for POWER also supported DLPAR, but its dynamic reconfiguration capabilities were limited to CPU capacity and PCI devices, but not memory.
Later on, the POWER5 processor added enhanced DLPAR capabilities, including micro-partitioning: up to 10 LPARs can be configured per processor, with a single multiprocessor server supporting a maximum of 254 LPARs (and thus up to 254 independent operating system instances).
Primarily, it is used to build agile infrastructures, or to automate hardware system resource allocation, planning, and provisioning.
IBM DB2 is such application (http://www.ibm.com/developerworks/eserver/articles/db2_dlpar.html), it is aware of the DLPAR events and automatically tunes itself to changing LPAR resources.