What is virtualization
Virtualization is an innovative solution that was pioneered by IBM on mainframes and then delivered on all IBM computing platforms. Virtualization allows the creation of software-based virtual machines (VMs) that appear just the same as physical servers, in which applications can be installed and optimized. The resulting virtualized workloads can then be managed as files and easily copied, modified or archived.
Why care about virtualization
Virtualization provides a quick and easy way to reduce costs, improve service levels and manage risk. Better still, most of these benefits can be realized immediately upon deployment, freeing up administrator time and IT resources for other projects.
POWER® processor-based servers are unique among UNIX® and Linux® servers in that they support the same virtualization product, PowerVM™, and almost all of the same virtualization features in servers ranging from blades to high-end servers. The features of PowerVM are even more impressive.
PowerVM outperforms, outscales and outlasts the competition
Higher resource utilization: PowerVM allows clients to achieve higher resource utilization. Power Systems are designed to support the maximum consolidation. They have more underlying hardware infrastructure which eliminates constraints that can inhibit utilization of processor resource. Unlike other RISC and EPIC based servers, PowerVM separates physical processors from logical processors and unlike x86 and EPIC resource sharing virtualization technologies, PowerVM supports the flexibility of devoting almost the whole physical system to the high priority virtual machines when they need the resource.
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IBM, Sun, and HP each have a virtualization technology that works with UNIX and supports shared processors. Sun Logical Domains (LDOMs) run on their CMT systems. With LDOMs, the logical processors are associated with threads and threads are associated with specific cores. HP’s Integrity Virtual Machines (IVM) associates logical processors with specific cores when a partition is started.
You can think of this as like a queue at a bank. With LDOMs or IVM, each customer (logical processor) can only go to one teller (physical core) every time they go to the bank. If there are many clients who need the same teller, they will wait longer for service, even though other tellers are idle. In order to meet service level objectives, the bank has to assign fewer clients to each teller. That increases the number of tellers. More tellers (cores) with the same total workload lead to lower utilization.
With PowerVM, there is a single line for all clients. The client at the head of the line gets the next available teller. This makes best use of the physical cores and minimizes the wait time for the logical processors to be dispatched
Using virtualization to maximize consolidation usually requires many partitions to share each processor core. The processor capability may not be the constraining technology. Power Systems deal with this by supporting more memory per core, memory bandwidth per core, I/O bandwidth per core and L2 and L3 cache per core than any other UNIX, Linux or Windows® servers. This minimizes constraints which inhibit maximum utilization.
Customers who are consolidating frequently run out of memory before they run out of processing capability. Having more memory per core helps Power Systems overcome that. We also have two other technologies that help relieve this constraint, Active Memory™ Sharing and Active Memory Expansion. Active Memory Sharing is a feature of PowerVM which supports memory sharing through memory over commitment similar to the way the shared processor pools support over commitment of processors to increase utilization. Active Memory Expansion is a hardware feature that uses compression / decompression algorithms to make physical memory look like as much as two times its actual size to a partition. Active Memory Expansion is enabled on a partition basis. Only a few of our competitors offer Active Memory Sharing and none of them offer Active Memory Expansion.
Similarly many customers will be limited by I/O capability. Having greater I/O bandwidth provides a basis for greater utilization. PowerVM goes beyond that with flexible I/O capabilities for virtualized environments. VIOS supports sharing of I/O and network adapters to increase their utilization, including shared storage pools that can be accessed from multiple servers. However, sometimes an application might need to own the whole I/O capability to meet service level objectives. Therefore PowerVM also supports direct attachment of the I/O adapters to the partition. Competitors’ virtualization technologies do not allow the same flexibility in I/O control.
Flexibility and scalability: PowerVM runs on all POWER7® systems from blades to the Power® 795. It supports partitions that can range in size from using 10% of a processor core through to using all processor cores available on the system - up to 256 cores on the Power 795!
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PowerVM supports the broadest range of servers of any UNIX, Linux, or Windows virtualization technology. PowerVM runs on the entire POWER6 and POWER7 processor-based product lines, and - unlike competing products - a single VM can utilize all of the processors and memory installed on the system.
Oracle/Sun systems use different virtualization technologies for different server lines and system classes. If clients reconfigure their servers by consolidating small servers to larger servers, they must reconfigure their partitions.
HP Integrity Virtual Machines and VMware both have a limit of eight logical processors per partition. This limits their use to small and medium partitions. The other HP virtualization technologies, nPars and vPars do not allow core sharing.
So, for example, if a client decided to consolidate several servers, each running a couple of partitions with 16 virtual CPUs, to one larger server, with PowerVM, they would not have to redefine the partitions. They would simply move them.
With HP or x86, since the maximum was eight logical processors, they would be moving from a non-virtualized environment. Only PowerVM has the scalability and flexibility to satisfy changing requirements.
Availability: Live Partition Mobility helps clients eliminate hardware related planned downtime. Just move the partition while it is running to another server so you can upgrade or maintain hardware without interrupting productive work.
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Consolidation drives increased focus on availability. Increasing the number of workloads and users on a server increases the potential disruption if the server is down. Power Systems are ready for consolidation with many built-in reliability features designed to minimize disruptions. A study by ITIC study has shown that AIX® systems are the most reliable among UNIX, Linux, and Windows systems.
The increased demand for availability of consolidated systems has led to the development of new features like Live Partition Mobility in PowerVM. In addition, PowerVM also has the capability to support multiple VIOS partitions to provide redundancy in the shared I/O by eliminating the single points of failure in the I/O subsystem.
No more planned outages for applications because of hardware upgrades or reconfiguration. Instead of stopping the application, just move it. Live Partition Mobility can help clients eliminate all hardware related planned interruptions. Virtualization technologies from Sun do not have any equivalent.
The solution: PowerVM virtualization without limits
Using virtualization to consolidate server workloads is an effective way to regain control of energy and management costs. The more workloads you can virtualize, the more you can save. But you still need to deliver effective service levels and maintain high availability after consolidation. PowerVM delivers for you: higher resource utilization, greater flexibility and scalability to help consolidate more workloads and the best availability in the industry.