VDC 2.0 Glossary

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affinity group. Virtual machines can be associated with each other by including them in affinity groups. For the group type 'anti-affinity', VMs in the same group will not run on the same hypervisor, and will be automatically distributed across several hypervisors. This makes it easy to build a resilient solution using multiple VMs.

Allocated IOPS disk. An Allocated IOPS disk is a high-performance storage disk based on the SSD EBS disk medium with a guaranteed minimum IOPS performance.

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CIDR notation. An abbreviation for Classless Inter-Domain Routing. CIDR notation is a compact way to specify ranges of IP addresses. For example, '' denotes all the IP addresses in the range to The prefix mask (the number after the '/') is required even for a single IP address: this is written with a '/31', for example ''. CIDR notation is used in VDC to configure network IP ranges, firewall rules and egress rules. The special address '' is used to refer to all IP addresses; for example, when you want to create a firewall rule for a VM to be accessible to any computer on the Internet.

Interoute CloudStore. The Cloudstore (http://cloudstore.interoute.com) is a product marketplace and the information site for Interoute VDC. You can browse for, and purchase, applications and services, which will be deployed automatically to VDC.

compute offering. See service offering.

console. The console is the primary interface to a virtual machine, equivalent to logging in directly using the screen and keyboard of physical computer hardware. You can access the VM console by using the 'Virtual Machines' panel of the VDC Control Centre.

VDC Control Centre. The control centre is the graphical interface where you monitor and control the resources of your VDC. It is accessed via the My Services portal.

Customer ID. The Customer ID is the identifier which is attached to all of the services and transactions that you have with Interoute. It consists of five letters or numbers. For example: 'INUE0', 'CLOV6'.

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dashboard. In the VDC Control Centre, the dashboard is the default view panel showing the status of your virtual machines and networks.

data disk. A virtual storage disk used for storing application data and user data. It can be physically deployed on magnetic disk (EBS) or solid-state disk (EBS SSD), and with or without automated backup ('protected'/'mirrored' disks are regularly copied to one/two backup locations). Compare root disk.

default login. When you create a VM, some templates have a default username and password for the administrator/root user. These details can be requested from Interoute Support. You are strongly recommended to change default passwords as soon as a new VM is created. If the VM is accessible from the Internet it is very likely to be the subject of a brute force password attack. You should use strong passwords or, preferably for Linux/Unix machines, you should disable password login and use SSH with public key authentication.

destroyed VM. When a VM is destroyed it is first switched off and set to 'Destroyed' state. It will be removed from VDC after the expunge interval has elapsed. During this time the VM can be recovered.

Direct Connect Group. A Direct Connect Group (DCG, also known as a 'VRF') creates private network inter-connections between Private Direct Connect networks in different zones of VDC. The networks form a mesh architecture with local network addressing (RFC 1918) between all of the networks. It is also possible to create inter-connections in the same DCG with Interoute VPN networks or third-party VPN networks.

disk offering. The disk offerings are the available storage types when you create a data disk. A set of fixed-size disk offerings is also available, which are only for use when you create a virtual machine root disk from an ISO.

dynamically scalable VM. A VM which is dynamically scalable can have its number of CPUs and its RAM memory (the service offering) changed while the VM is running. Only scaling up is allowed: the RAM size or number of CPUs must stay the same or increase. A stopped VM can have its service offering altered to any of the available offerings.

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EBS (external block storage). EBS is a block-based storage type available in VDC, based on physical magnetic disc. It can be configured in a choice of three tiers: unprotected, protected (automated snapshots are stored within the same data centre), or mirrored (also known as 'protected offsite' — — the automated snapshots are stored within the same data centre and also copied to a second data centre). See also SSD EBS disk. An alternative storage service offered by Interoute is object storage.

egress rule. Egress rules control the outbound network connections from your VDC. Each egress rule specifies a range of ports and the VMs that are allowed to use that egress.

expunge interval. The period of time that elapses between the deletion of a storage volume, or destruction of a VM, by a user and its permanent removal from VDC. The value for VDC is 72 hours. During this interval the resource can be recovered (for a VM, there is a recover function in the Control Centre; for a volume, you should make a request to Interoute Customer Support).

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firewall rule. Firewall rules control the network traffic into and out of your VDC. Each rule specifies whether an individual port (or range of ports) is active and which VMs can be reached through that port. Outbound traffic is normally controlled using egress rules. When you create a network in VDC, its firewall is initially set to 'deny all' and no external connections are set up by default.

forced stop. A virtual machine can be given a forced stop (with the API call stopVirtualMachine) which means that the VM is given 'stopped' status in the VDC database, even when the hypervisor fails to report a successful VM stop for any reason. You must be certain that a VM has actually stopped before executing a forced stop command, or contact Interoute Support to check the state of the VM at hypervisor level.

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hypervisor. A hypervisor is a kind of management software which runs multiple virtual machines on a single physical computer, dynamically sharing the computer's CPU, memory and storage resources according to the varying requirements of each VM; the hypervisor also ensures that there is no communication of data or programs between the VMs.

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Infrastructure-as-a-Service (IaaS). IaaS is a commonly-used term which denotes a cloud-based computing service where 'raw' computing resources are provided and the customer takes responsibility for the installation and management of operating systems, storage and network devices, and application software. See also Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). Read more about IaaS at www.interoute.com.

instance. An instance or 'VM instance' is another way of referring to a virtual machine. (Every VM can be thought of as an instance of the template which defined its creation.)

ISO image file. An ISO file is used to store software, typically an operating system or application software. You can upload new ISO files into VDC. You can use ISO files as a basis for creating new VMs. The ISO file format was originally created for use in CD-ROM/DVD-ROM optical media. In cloud computing an ISO file is used as a virtual equivalent to a physical DVD-ROM.

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load balancing. This is a network configuration option where incoming network traffic (for example, website page requests) is distributed across a set of VMs according to an algorithm that aims to balance the traffic load on each VM.

Local with Internet Gateway network. A network with Internet connection and related services for firewall, NAT (port forwarding), load balancing and IPSEC VPN.

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My Services portal. My Services is the web portal to all of Interoute's services: https://myservices.interoute.com. You use your VDC username (usually your email address) and password to login.

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NAT. The NAT (Network Address Translation) configuration of each 'Local with Internet Gateway' network in your VDC controls how virtual machines, which are directly connected only to an internal network, may communicate with the public Internet.

network. In cloud computing, a network is a virtual implementation of the hardware that provides a local area network (router, firewall, and connecting cables), in some cases with outward connections ('IP addresses') to public or private external networks (public internet, internet-based VPN, or private fibre network). From the user's perspective this virtual network is configured and operates using the same protocols (TCP, UDP, ICMP) and functions as a physical network.

NIC. The NIC (Network Interface Controller) is a 'virtual device' attached to the VM which enables the connection of the VM to a network. Each VM may have multiple NICs and network connections simultaneously. Then, as for a physical computer, you use the network routing software in the operating system to control how network connections are routed to the different available networks.

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object storage. Interoute Object Storage is a low-cost, high availability distributed storage service. It is closely-integrated with the VDC platform and the Interoute core network to ensure rapid data transfers.

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persistent VM. See virtual machine (VM).

Platform-as-a-Service (PaaS). PaaS is a commonly-used term which denotes a cloud-based computing service where customers are provided with managed software applications (for example, a webserver and database 'stack'), and the management of VMs and all system administration is taken care of by the service provider. See also Infrastructure-as-a-Service (IaaS) and Software-as-a-Service (SaaS). Read more about PaaS at www.interoute.com.

Private Direct Connect network. Private Direct Connect networks use Interoute's global fibre network to offer high speed and high-capacity networks which can connect your VMs in any of the VDC zones. Each Private Direct Connect network (within one VDC zone) belongs to a Direct Connect Group, which enables the inter-connection between the zones.

Public Direct Connect network. A network consisting of a sequence of directly-allocated public IP addresses, that is, direct connections to the Internet. This network type is intended for use with VMs running dedicated firewall or load balancing/traffic management applications. There is no network-based firewall for these network connections, so all connected VMs must be fully-protected for exposure to the Internet.

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recurring snapshot. See snapshot.

region. See VDC region.

root disk. When a VM is created a dedicated storage volume of type ROOT is created to hold the VM operating system. It is not recommended to store user data or application data on a root disk; one or more data disks should be used for this purpose.

running VM. See virtual machine (VM).

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Service Identifier (SID). The SID is a unique identifier for a particular Interoute service that you are using. This identifier consists of your Customer ID (for example, 'INUE0'), plus a service type code (e.g. 'VDCC' for your main VDC service), plus a numerical ID number; for example: 'INUE0/VDCC/145678'.

service offering. The service offering of a VM is its compute capacity in terms of the effective number of CPUs and the RAM memory. The initial service offering is selected during the creation of a VM and the offering can be changed at any time for a stopped VM, and also while the VM is running in the case of a dynamically scalable VM.

snapshot. A volume snapshot is a copy of a storage volume, captured at a point in time. Snapshots can be taken manually, or as recurring snapshots taken automatically at scheduled intervals, ranging from hourly to monthly. To make use of the data in a snapshot, you can convert it to a data disk, and attach that to a VM in order to access the archived data. A root disk snapshot can be converted to a template, which can be used to create VMs. A virtual machine snapshot is a record of a running VM, taken at one point in time: A Disk VM snapshot contains the disk volume data and metadata (configuration information) of the VM. It is also possible to capture the VM memory state (RAM) in a DiskAndMemory VM snapshot. VM snapshots are not recommended for use as data backups. They are recommended only to be used as a 'roll back' backup during planned works (e.g, a system upgrade), and should be removed afterwards.

Software-as-a-Service (SaaS). SaaS is a commonly-used term which denotes a software application that is provided through a cloud-based computing service. The management of the software and the underlying VMs, storage and network resources is taken care of by a service provider (or possibly several providers). See also Infrastructure-as-a-Service (IaaS) and Platform-as-a-Service (PaaS). Read more about SaaS at www.interoute.com.

SSD EBS disk. SSD EBS is an implementation of External Block Storage using solid-state physical disk media. It can be deployed as 'unprotected' or 'protected' (automated snapshots are stored within the same data centre). See also EBS (external block storage).

stopped VM. See virtual machine (VM).

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template. A template is a software source for a virtual machine, consisting of a base operating system (in VDC, the standard OS choices provided are Windows Server 2008, 2012 and 2016; Red Hat Linux, CentOS Linux, and Ubuntu Linux) and application software. You can use snapshots to create your own templates with application software ready-installed for your own requirements. Also you can upload your own templates into VDC.

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UUID. Abbreviation for universally unique identifier. 'Version 5' UUIDs are used to identify resources in VDC. These are sequences of 32 hexadecimal digits grouped 8-4-4-4-12 with hyphens. Example: fc129b38-d490-4cd9-acf8-838cf7eb168d .

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virtual data centre (VDC). A Virtual Data Centre is an abstraction of a physical data centre. It offers the same infrastructure (network, storage and compute) in a virtualised environment; it offers Infrastructure-as-a-Service (IaaS). You can get the cloud capacity that you need on demand, and only pay for what you use.

VDC region. VDC's zones are structured into three global regions: Europe, North America and Asia. Each region has its own Control Centre interface for the control of VDC resources in the zones of that region.

VDC zone. Each VDC zone is a physical data centre where compute, storage and network router hardware are located. The zones are inter-connected (in Europe) by Interoute's self-owned fibre network. Using the zone options in VDC you can control precisely where your data is stored and where your computer processes are run.

virtual machine (VM). A virtual machine is a software implementation of a machine that executes programs like a physical machine. In VDC, VMs are persistent by default. Their state can be running or stopped - with idle processors but holding their storage and network configuration ready to be re-started (but note that charging continues for CPU, RAM, storage volumes, and for the storage of any VM snapshots).

virtual router (VR). A virtual router is a virtual network device which supports the virtualised network functions in Virtual Data Centre. As well as providing standard network functions (such as DHCP lookup of IP addresses, firewall and load-balancing functions, NAT control of ingress and egress ports), the VR also provides a means of communicating information between the VDC orchestration system and the virtual machine operating system. VRs exist in three types of VDC network (Local with Internet Gateway, Private Direct Connect and Public Direct Connect), but do not exist in Local Private networks.

VM snapshot. See snapshot.

VR. See virtual router.

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zone. See VDC zone.

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