1.1 PowerVM Features
Below are some of the technologies and features of PowerVM.
PowerVM Hypervisor (PHYP): This functionality is made available by the hardware platform in combination with system firmware for the POWER server. The hypervisor is ultimately the basis for any virtualization on a POWER system.
Logical Partition (LPAR): LPARs are provided through the hypervisor. Originally, only dedicated hardware components and complete processors could be allocated to an LPAR; only the memory was shared. In the course of the Power Systems generations, the possibilities have been expanded further and further (micro-partition, dynamic logical partition), although the term LPAR has been retained.
Micro Partition: The micro partition allows a processor to be shared between different partitions. The micro partitions are assigned parts of a processor, which is also referred to as shared processor partitions.
Dynamic Logical Partition (DLPAR): Virtual resources (CPU, memory, physical adapters and virtual adapters) can be added to or removed from the partition at runtime (provided that the operating system supports it). This means that resources can be dynamically adapted to the needs of a partition.
Shared Prozessor Pools (SPP): Partitions can be assigned to shared processor pools, so that the consumption of processor resources by partitions can be limited to the resources available in the pool.
Virtual I/O Server (VIOS): This is a special service partition with an AIX-based, specially extended operating system for supporting a range of virtualization functions. Network adapters (Virtual Ethernet) and I/O adapters (Virtual SCSI and Virtual FC) can be virtualized via virtual I/O servers.
Virtual Ethernet (VETH): Client partitions can communicate in the network with the help of virtual Ethernet adapters without having their own physical Ethernet adapters.
Virtual SCSI (VSCSI): With the help of the virtual I/O server, client partitions can access disks via a virtual SCSI adapter without having their own physical I/O adapter. The necessary physical adapters belong to the virtual I/O servers and can therefore be shared by many partitions. The disks must be assigned to the virtual SCSI adapters.
Virtual FC (VFC): In contrast to Virtual SCSI, Virtual FC allows a virtual FC adapter to be assigned directly to a physical FC adapter. Unlike with VSCSI, the individual disks no longer have to be assigned to the virtual adapters, which makes administration much easier.
Live Partition Mobility (LPM): This feature allows an active partition to be moved online from one power system to another power system. All applications and the operating system simply continue to run during the online move. From the point of view of the applications, the move is transparent.
Active Memory Expansion (AME): By compressing main memory, additional available main memory can be obtained. The desired compression can be specified. With this, for example, from 32 GB of physical main memory and a compression factor (AME factor) of 1.5, 48 GB of main memory can be obtained for one partition. The operating system and all applications see 48 GB of available main memory.
Single Root I/O Virtualization (SR-IOV): With this type of virtualization, a virtual I/O server is no longer required. The virtualization takes place in hardware directly on the physical adapter. With PowerVM this is currently limited to SR-IOV capable network adapters. The bandwidth of the SR-IOV Ethernet ports can be divided between the individual partitions.
Virtual Network Interface Controller (vNIC): Allows automatic failover to another SR-IOV Ethernet port if one SR-IOV Ethernet port fails. For this, however, the support of virtual I/O servers is required again.
Some other features of PowerVM were not included in this overview.