For organizations that want to extend their PowerVM workloads to the cloud, PowerVS offers a straightforward path to implementing a hybrid cloud. But IT teams should understand how PowerVS works and what it can provide before committing to the service.
Power Systems Virtual Server, or PowerVS, is an IBM infrastructure as a service (IaaS) offering that enables Power Systems customers to extend their on-premises environments to the cloud. The PowerVS service is built on Power Systems servers that run the PowerVM virtualization platform, providing a hosted infrastructure that integrates seamlessly with on-premises systems.
What is Power Systems Virtual Server?
The Power Systems servers that support PowerVS are located in the IBM data center but kept separate from the IBM Cloud servers. PowerVS servers are on their own fenced networks with dedicated direct-attached storage, with an architecture identical to certified on-premises Power Systems infrastructure. PowerVS provides a secure environment in which to deploy virtual servers — also known as logical partitions (LPARs) — that incorporate the reliability, availability and serviceability features inherent in the Power Systems platform.
With PowerVS, customers can quickly deploy one or more virtual servers, each running an AIX, IBM i or Linux OS. PowerVS provides AIX and IBM i stock images, but customers must provide their own Linux images, which should conform to the Open Virtual Appliance format. PowerVS supports both Red Hat Enterprise Linux and SUSE Linux Enterprise Server for the Linux images. Customers can also bring their own customized AIX or IBM i images.
When administrators set up virtual servers, they must choose the data center where the virtual servers will be located. IBM offers data centers in multiple locations around the world. Customers must also select the Power Systems hardware — the machine type — to host the virtual servers from the following selection:
- IBM Power System E880 (9119-MHE)
- IBM Power System E980 (9080-M9S)
- IBM Power System S922 (9009-22A)
The data center location determines what hardware is available. For example, the Washington, DC, data center supports Power Systems E980 and S922, and the Dallas data center supports Power Systems E880 and S922.
Power Virtual Server and IBM Cloud
Because PowerVS is a cloud service, administrators can deploy one or more virtual servers quickly through the IBM Cloud catalog. When setting up a virtual environment, they can choose the number of virtual server instances, number of cores, amount of memory, network interfaces and data volume sizes and types. Administrators manage guest OSes and any middleware, runtime, data and applications they want to run on those virtual servers. IBM manages the underlying network, storage and server resources, as well as the PowerVM environment.
PowerVS automatically restarts virtual servers on a different host if a hardware failure occurs. IBM also offers optional services to increase availability or support disaster recovery. For example, customers can opt for PowerHA SystemMirror for AIX or Geographic Logical Volume Manager replication. In addition, customers can choose to soft pin or hard pin a virtual server to the host. Soft pinning increases availability but might not be possible because of licensing restrictions.
PowerVS provides identity and access management services that enable customers to control access to virtual server resources. Customers can also set affinity and anti-affinity policies to control the placement of new storage volumes.
Because PowerVS is an IaaS offering, users receive many of the same advantages they’d get from other cloud offerings. They can avoid the Capex attached to on-premises infrastructure and reduce the time IT teams spend to implement and maintain infrastructure. In addition, customers can migrate workloads easily from their on-premises Power Systems servers to PowerVS virtual servers because PowerVS is built on the same foundation.
This consistency across environments also means that PowerVS customers access the same IBM enterprise services that they use in their on-premises systems. Plus, PowerVS supports the Red Hat OpenShift container platform, making it possible to provision an OpenShift cluster on virtual server instances. PowerVS is also a certified off-premises Power Systems solution for SAP HANA and SAP NetWeaver workloads.
PowerVM is a virtualization platform built into Power Systems servers. The platform provides Power Systems Virtual Server with the necessary foundation to support virtual servers running AIX, IBM i or Linux workloads. PowerVM consists of hardware, firmware and software components that together enable IT admins to virtualize CPU, storage and network resources. At the heart of the platform lies the Power hypervisor, which provides an abstraction layer between the LPARs and physical hardware resources.
LPARs are self-contained operating environments similar to the VMs supported by other hypervisors. A Power Systems server can support up to 1,000 LPARs. Administrators can assign processor, memory and I/O device resources to each LPAR at a granular level. PowerVM also includes Virtual I/O Server, a software component that enables multiple LPARs on a server to share physical I/O resources.
PowerVM integrates seamlessly into the Power Systems platform, providing a secure environment for workload integrity protection, while enabling IT admins to use server resources effectively. IT teams can scale up or scale out their virtualized deployments without incurring performance penalties. PowerVM also offers Active Memory Sharing (AMS), which makes it possible to reallocate memory from one LPAR to another. In addition, PowerVM supports live partition mobility for LPARs migration between systems, helping to streamline upgrades and system balancing.
PowerVM also offers a number of other important features:
- micro-partitioning technology for locating fractions of processing resources to LPARs;
- multiple shared processor pools for automatically balancing processing power across LPARs;
- PowerSC suite of security components, including Trusted Boot, Trusted Logging and Trusted Firewall;
- single-root I/O virtualization, which provides optimized I/O virtualization within the network adapter’s hardware;
- dynamic logical partitioning for dynamically moving processor, memory and I/O resources between LPARs;
- active memory deduplication, which reduces memory consumption for AMS configurations; and
- shared storage pools to optimize resource consumption.
PowerVS is a full IaaS offering, whereas PowerVM is strictly a virtualization platform, whether implemented on premises or as part of PowerVS. If organizations implement PowerVM on premises, they deploy and maintain the platform, as well as the underlying infrastructure that supports it.
PowerVS vs. on-premises PowerVM
Organizations committed to the Power Systems platform in their on-premises data centers can use PowerVM to virtualize workloads, improve server resource consumption and simplify infrastructure management. They can also deploy their workloads to Power Virtual Server, which uses PowerVM to create and maintain virtual servers. More importantly, PowerVS enables an organization to implement a hybrid cloud that extends its on-premises environments to PowerVS. In fact, PowerVS was designed primarily to support this scenario.
For most Power Systems customers, the choice isn’t between PowerVM and PowerVS, but rather between an on-premises deployment and a hybrid deployment that extends their virtualized workloads to PowerVS:
- With an on-premises offering, customers maintain full control over their environments and avoid long-term subscription fees — which add up quickly — but they also face the initial Capex that goes with acquiring equipment, along with the time and costs of ongoing maintenance.
- With a hybrid deployment, customers can extend their environments easily to the cloud, deploy workloads to multiple global data centers and lower Capex and maintenance overhead. However, those customers must still maintain their on-premises infrastructure with the addition of cloud subscription fees.
Customers can use PowerVS exclusively and forego on-premises Power Systems infrastructure. Like any cloud service, this setup has advantages and disadvantages.
In either scenario, customers are locking themselves into the Power Systems platform. Although this can simplify licensing, management and workload integration, it has limitations — such as the inability to run Windows OS on the virtual servers. Customers must also pay and track ongoing subscription fees if they use PowerVS alone or in a hybrid configuration.