Glossary

An Oracle VM Server dedicated to performing administrative functions on storage servers such as creating a new LUN or extending a file system. The server must be capable of logging into a storage array or file server as an admin user. The administrative functions available to the server are defined by the Oracle VM Storage Connect plug-in.

Specify that specific virtual machines should always run on the same host.

An infrastructure template containing a configuration of multiple virtual machines with their virtual disks, and the inter-connectivity between them. Assemblies can be created as a set of .ovf (Open Virtualization Format) and .img (disk image) files, or may all be contained in a single .ova (Open Virtualization Format Archive) file.

Bonding is a Linux OS feature that provides a method for aggregating several ports into a single bonded interface, to provide load balancing or redundancy. When you discover an Oracle VM Server, the bonded interface is shown as containing a single port.

Network bonding refers to the combination of network interfaces on one host for redundancy and/or increased throughput. Redundancy is the key factor: You want to protect your virtualized environment from loss of service due to failure of a single physical link.

In Oracle VM, there are three modes of network bonding:

The action or result of making an exact copy of an object. The object may be a virtual machine, virtual machine template, ISO file, or virtual disk. Cloning is analogous to copying and maintains the integrity of the original object, while creating a new object based on the original. A clone customizer may be used to define cloning options to specify details of where the object components may reside when cloned, such as in a different storage repository.

A privileged domain that creates and manages other logical domains and services.

The process of adding systems as objects within Oracle VM Manager is known as discovery. When you add Oracle VM Servers and storage to your Oracle VM environment, Oracle VM Manager uses the information provided to connect to the resource and perform verification. During this process, information is usually exchanged between the server and the manager. In the case of an Oracle VM Server, Oracle VM Manager obtains information about the server, its network connectivity and any storage that is already attached to the server. Depending on your hardware and networking configuration, external storage may be automatically detected during discovery of Oracle VM Servers. This is always the case with local OCFS2 storage on an Oracle VM Server.

While storage can be automatically discovered during the process of discovering Oracle VM Servers, you may need to perform storage discovery for resources that are not already attached to any of your Oracle VM Servers. It is important that storage is configured outside of the Oracle VM environment prior to discovery. Depending on the storage type, you can perform different storage discovery operations from within Oracle VM Manager.

DPM complements DRS to reduce the Oracle VM Servers in a server pool when there are periods of low resource utilization. It can automatically add capacity as needed when resource utilization ramps up.

See Also: distributed resource scheduling

DRS provides real-time monitoring of Oracle VM Server utilization with the goal to rebalance a server pool to provide consistent resources to the running virtual machines. DRS migrates load away from heavily loaded Oracle VM Servers to less heavily loaded Oracle VM Servers.

See Also:distributed power management

An abbreviation for domain zero. The management domain with privileged access to the hardware and device drivers. Dom0 is the first domain started at boot time. Dom0 has more privileges than domU. It can access the hardware directly and can manage the device drivers for other domains. It can also start new domains.

A configurable set of resources, including memory, virtual CPUs, network devices and disk devices, in which virtual machines run. A domain is granted virtual resources and can be started, stopped and rebooted independently.

See Also: dom0

See Also: domU

An unprivileged domain with no direct access to the hardware or device drivers. Each domU is started by dom0.

Events are used to register status information of "objects" within Oracle VM Manager for future reference or to make problems easier to trace back. Events are often, though not always, related to jobs that are initiated within Oracle VM Manager. For instance, when a job fails, an event is generated. Events can also be triggered through changes in the environment such as server crashes or storage disconnects. Therefore, events are used to alert you to potential problems that may need your attention.

Events are categorized by severity. Most events will be informational, but they can also be warnings or errors. If an event has an error level severity, you need to acknowledge the error event to clear the error and to perform further operations on the object that generated the error.

See Also: jobs

A guest operating system that runs within a domain in Oracle VM Server. A guest may be paravirtualized or hardware virtualized. Multiple guests can run on the same Oracle VM Server.

Hard partition, or CPU pinning, is the act of binding a virtual machine to one or more physical CPUs or cores. This prevents software within the virtual machine from running on any cores other than those specified for the virtual machine. By default, Oracle VM takes advantage of distributed resource scheduling, which allows a virtual machine to use all cores on an Oracle VM Server as required. In some situations, such as the requirement to conform with Oracle licensing policies for partitioned environments, it may be desirable to implement hard partitioning.

Hard partitioning can result in restrictions on live migration, DRS and DPM.

A hardware virtualized guest runs on the virtualization platform as it would on a physical host. Because the device drivers of the hardware virtualized guest are emulated, dom0 must contain device emulation code to support the guest’s device drivers. The other types of privileged instructions issued by the hardware virtualized guest, for example, for CPU or memory access, are not emulated, but are trapped, which also requires support from CPU vendors.

The guest’s OS does not require any modification to run as a hardware virtualized guest.

A virtual machine with an unmodified guest operating system. It is not recompiled for the virtual environment. There may be substantial performance penalties running as a hardware virtualized guest. Enables Microsoft Windows™™ operating system to be run, as well as legacy operating systems. Hardware virtualization is only available on Intel® VT or AMD SVM CPUs.

High availability (HA) help ensure the uninterrupted availability of a virtual machine. If HA is configured for your virtual machine, and if the Oracle VM Server on which it is running fails or shuts down, the virtual machine is restarted on another available Oracle VM Server in the server pool. The server pool must be clustered. You must enable high availability for both the server pool and the virtual machine.

The physical computer on which the software is installed. Typically used to refer to either the computer on which Oracle VM Server or Oracle VM Manager is running.

A hypervisor, also called a monitor or Virtual Machine Manager (VMM), is a layer which abstracts the virtual hardware from the real hardware. As such it is the only privileged entity in the system which has full access to real hardware resources. It controls only the most basic resources of the system, including CPU and memory usage, privilege checks, and hardware interrupts.

Hosted hypervisors are designed to run within a traditional operating system. In other words, a hosted hypervisor adds a distinct software layer to the host operating system, and the guest operating system becomes a third software level above the hardware and the host-based hypervisor. A well-known example of a hosted hypervisor is Oracle VM VirtualBox. Others include VMware Server and Workstation, Microsoft Virtual PC, KVM, QEMU, and Parallels.

Native hypervisors are software systems that run directly on the host's hardware to control the hardware, and to monitor the guest operating systems. The guest operating system runs on a separate level above the hypervisor. Examples of this type of virtualization architecture are Oracle VM, Microsoft Hyper-V, VMware ESX, and Xen.

A method of protecting virtual machines on an Oracle VM Server by restricting whether new virtual machines can be created on it or migrated to it. By doing this, you can make sure the resources of an Oracle VM Server are available to the virtual machine(s) running on the server.

This feature overrides server pool policies and anti-affinity groups, and any of these other features or policies that can result in the migration of a virtual machine onto the Oracle VM Server. However, if you have HA configured for a server, this feature does not protect a server from inbound migrations when failover occurs.

Jobs are a sequential operations that take place through Oracle VM Manager, such as server discovery, presenting a repository and creating a VM. Jobs are assigned a status that is refreshed according to their progress. A history of all jobs in the environment is stored within Oracle VM Manager.

Since jobs are sequential and sometimes take time to complete, tracking the status of a job allows you to understand what actions the system is currently performing, and which actions are queued to run in sequence after the current job has completed. Jobs also allow you to access system messages that may be useful to debug the failure of an operation.

Most jobs tend to generate events that each have a different severity level.

See Also: events

Live migration is a process to move a running virtual machine from one Oracle VM Server to another, while applications on the existing virtual machine continue to run. You can only live migrate virtual machines from one Oracle VM Server to another within the same server pool.

Local storage consists of hard disks installed locally in an Oracle VM Server. Local storage is often not appropriate for production environments, because it prevents or sharply constrains the ability of a virtual machine to run anywhere in the server pool in the event of the failure of the Oracle VM server, which owns the local storage.

A virtual machine comprised of a discrete logical grouping of resources, which has its own operating system and identity within a single computer system. Also called a domain.

See Also: domain

A component of Oracle VM Agent. An application that acts as the contact point to Oracle VM Manager, and to other Oracle VM Agents. Provides virtual machine host load-balancing, and local persistence for Oracle VM Server.

There is only one master Oracle VM Server in a server pool. A physical server can perform as the master Oracle VM Server, Utility Server and Virtual Machine Server simultaneously.

Oracle VM supports a messaging system that enables communication between the Oracle VM Manager and a guest running within a virtual machine on any Oracle VM Server, as long as the guest has the Oracle VM Guest Additions installed. This messaging system works by sending key/value pairs between the guest and Oracle VM Manager via a secured connection. Messaging allows greater administrative control over virtual machines and facilitates remote and automated configuration of virtual machines as they are started.

The act of moving a virtual machine from one Oracle VM Server to another, or to the Unassigned Virtual Machines folder. Migration can be performed on either a running or a stopped virtual machine.

The act of moving an object from one location to another. This may be moving a stopped virtual machine from one Oracle VM Server to another, moving a virtual machine template from one storage repository to another, or moving an ISO file or virtual disk to another storage location.

The technique of creating more than one physical path between the server CPU and its storage devices. It results in better fault tolerance and performance enhancement. Oracle VM supports multipath I/O out of the box. Oracle VM Servers are installed with multipathing enabled because it is a requirement for SAN disks to be discovered by Oracle VM Manager

A clone of the type "non-sparse copy" is a disk image file of a physical disk, taking up the space equivalent to the full specified disk size, including empty blocks.

See Also: sparse copy

OCFS2 is a general-purpose shared-disk cluster file system for Linux capable of providing both high performance and high availability. OCFS2 is developed by Oracle and is integrated within the mainstream Linux kernel. OCFS2 is used within Oracle VM to facilitate clustered server pools, storage of virtual machine images and for the purpose of allowing guests to share the same file system.

A clustered server pool always uses an OCFS2 file system to store the cluster configuration and to take advantage of OCFS2's heartbeat facility. There are two types of heartbeats used in OCFS2 to ensure high availability:

These heartbeat functions exist directly within the kernel and are fundamental to the clustering functionality that Oracle VM offers for server pools. The server pool file system should be stored on a separate NFS server or on a small LUN if possible, as OCFS2's heartbeat facility can be disturbed by intensive I/O operations taking place on the same physical storage.

A storage repository configured on a LUN-based repository must be linked to a clustered server pool due to the nature of the OCFS2 file system. As a result, LUN-based repositories cannot be shared between multiple server pools, although it is possible to move an OCFS2 repository from one server pool to another.

For more information on OCFS2, please refer to https://oss.oracle.com/projects/ocfs2/.

An application installed with Oracle VM Server. The Oracle VM Agent receives and processes management requests, and provides event notifications and configuration data to the Oracle VM Manager. Oracle VM Manager manages the virtual machines running on Oracle VM Server by communicating with Oracle VM Agent. It contains three components: master Oracle VM Server, Utility Server, and Virtual Machine Server.

The Oracle VM Manager is the management platform, which offers an easy-to-use, web-browser interface as well as a command-line interface (CLI). The Oracle VM Manager tracks and manages the resources available in your virtual environment. The user interface, which is an Application Development Framework (ADF) web application, allow you to easily manage Oracle VM Server pools. Manages virtual machine life cycle, including creating virtual machines from templates or from installation media, deleting, powering off, uploading, deployment and live migration of virtual machines. Manages resources including ISO files, templates and shared virtual disks.

A self-contained virtualization environment designed to provide a lightweight, secure, server-based platform for running virtual machines. The Oracle VM Server comprises a hypervisor and a privileged domain (called dom0) that allow multiple domains or virtual machines (that is, Linux, Solaris, Windows, and so on) to run on one physical machine. Includes Oracle VM Agent to enable communication with Oracle VM Manager.

The Oracle VM Server for x86 incorporates an open source Xen hypervisor component, which has been customized and optimized to integrate into the larger, Oracle - developed virtualization server. The Oracle VM Server for x86 is also responsible for access and security management and generally acts as the server administrative entity, because the hypervisor’s role is limited.

On Oracle VM Server for SPARC systems, the SPARC hypervisor is built into the SPARC firmware and is generally referred to as the Logical Domains Manager (LDOM). As with the Xen hypervisor, each virtual machine is securely executed on a single computer and runs its own guest Oracle Solaris operating system

A virtual machine with a kernel that is recompiled to be made aware of the virtual environment. Runs at near native speed, with memory, disk and network access optimized for maximum performance.

Paravirtualized guests use generic, idealized device drivers, which are part of the guest’s OS. The I/O operations using these generic device drivers are mapped to the real device drivers in dom0. The generic, abstracted drivers in the guest seldom change and provide excellent guest stability. The dom0 domain, alternatively, can use the native hardware vendor drivers, and the guests can safely migrate to another dom0 with slightly different drivers.

For other resources such as CPU and memory, paravirtualized kernels make special “hypercalls” to the Xen hypervisor. These hypercalls provide better performance by reducing the number of instructions and context switches required to handle an incoming request. By contrast, on an emulated (hardware virtualized) guest, driver requests engage the guest’s interrupt handler, increasing the I/O operation overhead.

Also referred to as qemu-dm, which is the process name. The virtualization process which allows full virtualization of a PC system within another PC system.

Server pools logically organize one or more Oracle VM Servers into groups where virtual machines can run.

Each server pool can have up to 32 physical servers. Each Oracle VM Server can be a member of only one server pool. The server pool is the operational unit of Oracle VM. Policies are configured and enforced at the server pool level.

A minimum cluster of three Oracle VM Server nodes in each server pool is strongly recommended for high availability. If one node in the cluster experiences a hardware failure or is shut down for maintenance, failover redundancy is preserved with the other two nodes. Having a third node in the cluster also provides reserve capacity for production load requirements.

A server processor compatibility group is a group of Oracle VM Servers with compatible processors, or CPUs sharing the same processor family and model number. These groups are created to ensure that a virtual machine running on one Oracle VM Server can safely be migrated and continue to run on another Oracle VM Server. Oracle VM Manager automatically creates processor compatibility groups as it discovers servers that have different processor types.

Using Oracle VM Manager you can create custom compatibility groups to improve your ability to do smooth migrations and to group servers according to your own requirements.

Logical domain that provides devices, such as virtual switches, virtual console connectors, and virtual disk servers, to other logical domains.

A clone of the type "sparse copy" is a disk image file of a physical disk, taking up only the amount of space actually in use; not the full specified disk size.

See Also: non-sparse copy

Oracle VM integrates with all types of storage, referred to as generic storage, but also provides advanced storage functionality for storage vendors that provide a plug-in to access their storage. This plug-in is part of Oracle VM’s Storage Connect framework.

Oracle VM provides its own Oracle VM Storage Connect plug-in for the Sun ZFS Storage Appliance, and for the Oracle Axiom systems.

To initiate a connection to an iSCSI target, hosts use a client known as a storage initiator. The storage initiator is used to encapsulate SCSI requests in the iSCSI protocol and to handle requests and responses from the iSCSI target. Storage initiators are configured on each Oracle VM Server when an iSCSI Oracle VM Storage Connect plug-in is used.

A thin clone is a clone of a virtual disk that takes up only the amount of disk space actually in use; not the full specified disk size.

Thin cloning of virtual disks on OCFS2-based repositories is supported. Thin provisioning of physical disks on generic storage is not supported.

A component of Oracle VM Agent. An application that handles I/O intensive operations for virtual machines, server pools and servers, for example, copying, moving and renaming files.

There can be more than one Utility Server in a server pool. A physical server can perform as the master Oracle VM Server, Utility Server and Virtual Machine Server simultaneously.

A file or set of files, usually on the host file system although it may also be a remote file system, that appears as a physical disk drive to the guest operating system.

A guest operating system and the associated application software that runs within Oracle VM Server. May be paravirtualized or hardware virtualized machines. Multiple virtual machines can run on the same Oracle VM Server.

A template of a virtual machine. Contains basic configuration information such as the number of CPUs, memory size, hard disk size, and network interface card (NIC). Create virtual machines based on a virtual machine template using Oracle VM Manager.

A layer-2 network may be segregated into partitions, at the switch or router, so that network traffic is isolated to a distinct broadcast domain. VLANs can be tagged so that a trunk can transport data for all of the different VLANs in a network.

VLANs are commonly used in large networks to help simplify network design, provide mechanisms to achieve better scalability, and to improve security.

A component of Oracle VM Agent. An application which runs Oracle VM Server virtual machines. It can start and stop virtual machines, and collect performance data for the host and guest operating systems. Enables communication between the master Oracle VM Server, Utility Server and Virtual Machine Servers.

There can be more than one Virtual Machine Server in a server pool. A physical server can perform as the master Oracle VM Server, Utility Server and Virtual Machine Server simultaneously.

Oracle WebLogic Server is a platform that includes an application server that can run java applications within a web-based framework. Oracle VM Manager runs as an application within Oracle WebLogic Server, taking advantage of many of Oracle WebLogic Server's many features to deliver a robust web UI through which Oracle VM can be fully managed.

The installation process behind Oracle VM Manager automatically installs and configures Oracle WebLogic Server on the system where Oracle VM Manager is installed. During this process, a weblogic user is set up within Oracle WebLogic Server to manage Oracle WebLogic Server configuration and to administer the underlying system. An admin user is also set up within Oracle WebLogic Server and is given permission to access the Oracle VM Manager application. A typical setup uses the same password for both of these users, although this is not always the case and it is possible to configure a different password for each user depending on your requirements.

In general, users of the Oracle VM Manager application should avoid attempting to access the underlying Oracle WebLogic Server, or to change any configuration parameters here without guidance from Oracle Support.