Instances - Concepts
Block volumes provide network-attached storage that can be plugged 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.
The boot-on-block feature allows Instances to boot from attached Block Storage volumes instead of local volumes. This feature is available for all Instance types.
Cloud-init is a multi-distribution package that provides boot time customization for cloud servers. It enables automatic configuration of Instances as it boots into the cloud, turning a generic Ubuntu image into a configured server in a few seconds.
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 Instances are reliable and flexible Instances tuned to host your websites, applications, and development environments.
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 to 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. Find more information about the billing of dynamic IPs compared to flexible IPs on our billing FAQ.
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 of your Instances as 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 Instances are powerful Instances equipped with dedicated high-end Nvidia graphics processing units. See our dedicated GPU documentation for more details.
Creating an image allows you to make a complete backup of your Instance. One image will contain all of 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. To copy not all but only one specific volume of an Instance, you can use the snapshot feature instead.
An Instance is a computing unit, either virtual or physical, that provides resources to run your applications on. Currently Scaleway offers the following Instance types: General Purpose, Development, GPU, Stardust and Enterprise. For more information about the different ranges of Instance, see our dedicated documentation.
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.
The legacy public network is provided through a network component managing a carrier-grade NAT with private IP addresses. When an Instance is started, it is assigned a private 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 private IP assigned to the Instance during provisioning. Consequently, if the underlying node changes, the private IP address will also change.
With IP mobility, there are no private 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.
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).
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 at all, and boot directly on block volumes. In any case, it is always possible to increase the storage of a Virtual Cloud Instance by adding additional block volumes.
Unified snapshots are a type of snapshot that can be created from either local (LSSD) or block (BSSD) volumes. Unified snapshots can be used to create either LSSD or BSSD volumes, so they are more flexible than other snapshot types.
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 exact opposite: it brings Compute Instances closer together to achieve higher network throughput. Find how to use placement groups with our documentation.
Production-Optimized Instances (aka POP2) are compute resource 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
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.
Note: Depending on the amount of data to be archived, this process can take some time.
Private Networks allow your virtual Instances to communicate in an isolated and secure network without the need of being connected 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 a LAN-like layer 2 ethernet network. 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.
The Protected Instance feature is used to prevent 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 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.
Region and Availability Zone
A Region is as a Geographical area such as France (Paris:
fr-par) or the Netherlands (Amsterdam:
nl-ams) in which Scaleway products and resources are located. It can contain multiple Availability Zones.
An Availability Zone refers to the geographical location in which your Scaleway resource will be created. The latency between multiple AZs of the same region is low, as they have a common network layer.
For an extensive list of which regions and AZ a resource is available in, refer to our Products availability guide
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 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.
Security groups allow you to create rules to drop or allow 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. If you wish, you can then create your own private infrastructure by disabling the public IPs of your Instances. Security groups can be stateful to concept or stateless. Note that security groups for Elastic Metal servers cannot be stateful.
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.
An image is composed of snapshots of volumes. By default, snapshots can only be restored to a volume of the original type. Unified snapshots can be restored to a different volume type, for example to move from an instance with local storage to a block-only instance.
Stand-by mode is designed to temporarily stop an Instance. When you put an Instance in stand-by 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 different 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. Find out more with our dedicated documentation: 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, eg. 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 or not. Find out more with our dedicated documentation: how to use Security Groups
Tags allow you to organize your resources. This gives you the possibility of sorting and filtering your cloud assets in any organizational pattern of your choice, which in turn helps you arrange, control and monitor your cloud resources. You can assign as many tag 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 at all, and boot directly on block volumes.
Block volumes: Block volumes provide network-attached storage that can be plugged in/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.