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Instances - Concepts

Availability Zone

An Availability Zone refers to an isolated location within a specific region. Each Availability Zone provides its own services and infrastructure. For example, fr-par-1, fr-par-2, and fr-par-3 are Availability Zones within the Paris region.

For an extensive list of which regions and AZ a resource is available in, refer to our Product availability guide

Block volumes

Block volumes provide network-attached storage you can plug in/out of Instances like a virtual hard drive. From a user’s point of view, block volumes behave like regular disks and can be used to increase the storage of an Instance.


Boot-on-block is a feature that allows booting Instances from attached Block Storage volumes instead of local volumes. It is available for all Instance types.

Carrier-grade NAT (CGNAT)

Scaleway uses a 1:1 carrier-grade (CGNAT) setup for legacy Instance types. With this architecture, each Instance is assigned a unique NAT IP that directly maps to a unique public IP, unlike standard CGNAT, where multiple users share a single public IP. This setup ensures that all outbound and inbound traffic for an Instance is translated between these two addresses, preserving the exclusivity of IP addresses and avoiding certain connectivity issues related to a shared IP setup.


Cloud-init is a multi-distribution package that provides boot time customization for cloud servers. It enables an automatic Instance configuration as it boots into the cloud, turning a generic Ubuntu image into a configured server in a few seconds.

Cost-Optimized Instances

Cost-Optimized Instances are production-grade Instances designed for scalable infrastructures. Cost-Optimized Instances support the boot-on-block feature and allow you to launch high-performance services with high-end CPUs.

Development Instance

Development Instances are reliable and flexible Instances tuned to host your websites, applications, and development environments.

Dynamic IP

A dynamic IP is an alternative type of public IP address for your Instance. This type of IP address is detached and released back into the general public pool of IP addresses whenever you stop your Instance. This means when you next power on your Instance, it may get a different dynamic IP address. In this respect, dynamic IPs are different from flexible IPs, which remain associated with your Instance even when the Instance is stopped and are held in your account and can be moved between different Instances if you wish.

You can choose to give your Instance a dynamic IP address when creating or updating your Instance via the Scaleway API only. Read our billing FAQ for more information about the billing of dynamic and flexible IPs.

Flexible IP

Flexible IP addresses are public IP addresses that you can hold independently of any Instance. When you create a Scaleway Instance, by default, its public IP address is also a flexible IP address. Flexible IP addresses can be attached to and detached from any Instances you wish. You can keep a number of flexible IP addresses in your account at any given time. When you delete a flexible IP address, it is disassociated from your account to be used by other users. Find out more with our dedicated documentation on how to use flexible IP addresses. See also Dynamic IPs.

GPU Instance

GPU Instances are powerful Instances equipped with dedicated high-end Nvidia graphics processing units. See our dedicated GPU documentation for more details.


An image is a complete backup of your Instance. One image contains all the volumes of your Instance and can be used to restore your Instance and its data. You can also use it to create a series of Instances with a predefined configuration. If you wish to copy only a specific volume of an Instance, you can use the snapshot feature instead.


An Instance is a virtual computing unit that offers resources for running applications. It functions as a self-contained entity with its own operating system, RAM, and storage. Each type of Instance has unique specifications. You can choose the type that best meets your requirements. Refer to our Instance types documentation for further details on the various Scaleway Instance options.


An InstantApp is an image with a preinstalled application. By choosing an InstantApp when prompted to select an image during the creation of your Instance, you choose to install the specified application on your Instance. You can then start using the application immediately.

IP mobility

The legacy public network is provided through carrier-grade NAT infrastructure. When an Instance starts, it is assigned a NAT IP address that is associated with the underlying node hosting the Instance. The carrier-grade NAT establishes a one-to-one mapping between the public IP and the NAT IP assigned to the Instance during provisioning. Consequently, if the underlying node changes, the NAT IP address will also change.

With IP mobility, there are no NAT IPs anymore. The public IP is entirely routed to the Instance. The main benefit is that your underlying IP no longer changes when you stop and start your Instance or if it gets provisioned on another hypervisor. But this also means that if you do not attach a public IP address to your Instance, then it will not have any network access.


Your IP address will only be retained during stop/start operations if you have linked a flexible public IP address to your Instance. If you use a dynamic IP address, the behavior remains consistent, whether your Instance has a routed IP enabled or is a legacy one.

Learning Instance

Learning Instances are the perfect Instances for small workloads and simple applications. You can create up to one Instance per Availability Zone (available in FR-PAR-1 and NL-AMS-1).

Local volumes

The local volume of an Instance is an all-SSD-based storage solution, using a RAID array for redundancy and performance, hosted on the local hypervisor. On Scaleway Instances, the size of the local volume is fixed and depends on the Instance type. Some Instance types do not use local volumes and boot directly on block volumes. In any case, it is always possible to increase the storage of an Instance by adding additional block volumes.

Placement groups

Placement groups allow you to run multiple Compute Instances, each on a different physical hypervisor. Placement groups have two operating modes. The first one is called max_availability. It ensures that all the Compute Instances that belong to the same cluster will not run on the same underlying hardware. The second one is called low_latency and does the opposite, bringing Compute Instances closer together to achieve higher network throughput. Learn how to use placement groups.

Production-Optimized Instances

Production-Optimized Instances (aka POP2) are compute resources with dedicated resources (RAM and vCPUs). Designed for demanding applications, high-traffic databases, and production workloads.

Three variants of POP2 Instances are available:

  • POP2: Production-Optimized Instances with Block Storage.
  • POP2-HC: Workload-Optimized Instances, providing a ratio of vCPU:RAM of 1:8.
  • POP2-HM: Workload-Optimized Instances, providing a ratio of vCPU:RAM of 1:2.

Power-off mode

The Power-off mode shuts down an Instance by transferring all data on the local volume of the Instance to a volume store. The physical node is released back to the pool of available machines. The reserved flexible IP of the Instance remains available in the account.


Depending on the amount of data to be archived, this process can take some time.

Private Networks

Private Networks allow your virtual Instances to communicate in an isolated and secure network without requiring a connection to the public internet. Each Instance can be connected to one or several Private Networks, letting you build your own network topologies.

Private Networks are LAN-like layer 2 Ethernet networks. A new network interface with a unique media access control address (MAC address) is configured on each Instance in a Private Network. Use this interface to communicate in a secure and isolated network, using private IP addresses of your choice.

Protected Instance

Protected Instance is a feature that prevents any halt action from being performed on your Instance. This only applies to running Instances. Enabling the Protected Instance feature means that you will not be able to delete, power off, or reboot your Instance, nor put it into standby mode.

Public IP

Public IP addresses are routed on the internet. You can enter the public IP address of your Instance into any browser connected to the internet, and access content being served from that Instance. You can think of public IP addresses like postal addresses for buildings - they are unique and tell the routers directing traffic through the internet where to find a particular server.


A region is a geographical area such as France (Paris: fr-par), the Netherlands (Amsterdam: nl-ams), or Poland (Warsaw: pl-waw) in which Scaleway products and resources are located. Each region contains multiple Availability Zones.

For an extensive list of which regions and AZ a resource is available in, refer to our Product availability guide

Rescue mode

Rescue mode restarts your server via the network on a minimal operating system. You can use rescue mode to debug your server and recover your system data. Rescue mode creates a ramdisk with the content of a downloaded rootfs. You will have access to all your disks and will be able to perform debug and rescue actions. After disabling rescue mode, you will have to reboot your server. Your server needs to be running to switch to rescue mode.

Reverse DNS

Reverse DNS is the opposite of classic “forward” DNS, and maps an IP address to a hostname. This can be useful if, for example, you want to send emails from your Instance. Find out how to configure reverse DNS on your Instance with our how-to documentation.

Routed flexible IP

A routed flexible IP means assigning a public IP address to an Instance (virtual machine) that is reachable directly from the internet. This means there’s no address translation, and the Instance uses the public IP as its identity on the internet. The Instance can be accessed or can communicate directly using this public IP, which helps to make network configuration straightforward, with unrestricted inbound and outbound connections, crucial for services like web hosting or email servers.

Security group

Security groups allow you to create rules to drop or allow public traffic coming to and from your Instances. You can set default policies for inbound and outbound traffic, and/or define rules to deal with traffic differently depending on its source. Security groups can be stateful or stateless. Note that security groups for Elastic Metal servers cannot be stateful.


Security Groups only allow the filtering of public traffic to and from your Instances. To filter traffic within a Private Network, you can configure a firewall directly on your Instance, or use iptables or nftables from the command line interface of your Instance.


A snapshot takes a picture of a specific volume at one point in time. For example, you may have a server with one volume containing the OS and another containing the application data and want to use different snapshot strategies on both volumes. Creating snapshots of your volumes gives you total freedom of which volumes you want to back up, while images are more convenient for full backups of your Instance.

Snapshot type

An image is composed of snapshots of volumes. Snapshots can only be restored to a volume of the original type.

Standby mode

Standby mode is a way to stop an Instance temporarily. When you put an Instance in standby mode, the server is halted, but the Instance remains allocated to your account, and all data remains on the local storage of the Instance.

Stateful security groups

Stateful security groups disregard the default policy and inbound/outbound rules if a connection is initiated from your Instance. Traffic will always be permitted on connections that you initiated. This is useful for example if you want to initiate connections on many and various ports for messaging, video streaming, or other purposes. In this case, the traffic from/to that connection will not be blocked, even if you have defined a rule that would otherwise do so. Learn how to use security groups.

Stateless security groups

Stateless security groups strictly apply the default policy and inbound/outbound rules, regardless of whether a connection is initiated from your Instance or not. This is useful if you know exactly which ports you will always require for your Instance, e.g. port 22 for SSH. You can make your security group stateless, define a rule to allow traffic on port 22 and block incoming traffic on other ports regardless of whether a connection is initiated from your Instance on this port. Learn how to use security groups.


Tags allow you to organize, sort, filter, and monitor your cloud resources using any pattern you wish. You can assign as many tags as you want to each Scaleway product.


Volumes are the storage space of your Instances. Two types of volumes exist:

  • Local volumes: The local volume of an Instance is an all-SSD-based storage solution, using a RAID array for redundancy and performance, hosted on the local hypervisor. On Scaleway Instances, the size of the local volume is fixed and depends on the Instance type. Some Instance types do not use local volumes and boot directly on block volumes.

  • Block volumes: Block volumes provide network-attached storage you can plug in and out of Instances like a virtual hard drive. Block volumes behave like regular disks and can be used to increase the storage of an Instance.

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