Atlas Docs

Launch a VM

Properties1
aliasesInstances, Compute/Instances

3 min read

An Instance on Atlas Cloud is one virtual machine. You launch it with four ingredients: a Compute Offering (size), a Template (OS image), a Network, and an SSH key.

The fastest path is the Quickstart — five steps with copy-paste code for Console, CLI, Terraform, or curl. This page is the longer reference if you want to dive into any one step.

Compute Offerings

Atlas offerings follow the pattern Atlas.aN[w]:

NamevCPURAMFamily
Atlas.a414 GiBLinux
Atlas.a528 GiBLinux
Atlas.a6416 GiBLinux
Atlas.a7832 GiBLinux
Atlas.a7w832 GiBWindows
Atlas.a8w1664 GiBWindows

Pick the smallest that fits — you can resize later. For first-time experiments, Atlas.a4 is the cheapest. For real workloads, Atlas.a5 is the default.

# List the current set
cmk list serviceofferings filter=name,id,cpunumber,memory

Templates

A Template is the OS image your instance boots from. Atlas ships a featured set (Ubuntu 24.04 LTS by default). You can also import your own templates from a URL via Images → Templates → Register Template.

cmk list templates templatefilter=featured filter=name,id,ostypename

Launch the instance

The Quickstart shows this in four interfaces. The shortest path:

SO=$(cmk list serviceofferings name=Atlas.a4 | jq -r '.serviceoffering[0].id')
TMPL=$(cmk list templates templatefilter=featured name="Ubuntu 24.04 LTS" | jq -r '.template[0].id')
NET=$(cmk list networks name=my-network | jq -r '.network[0].id')
ZONE=$(cmk list zones name=is1 | jq -r '.zone[0].id')
 
cmk deploy virtualmachine \
  serviceofferingid=$SO templateid=$TMPL networkids=$NET zoneid=$ZONE \
  keypair=mykey name=hello-atlas

Network and SSH-key prerequisites are covered in Guest networks and SSH keys.

Lifecycle actions

Once running, an instance has these states and transitions:

ActionEffect
StopPowers down the OS. Compute is no longer billed; root volume still is.
StartPowers back up. Same root volume, same private IP.
RebootRestarts the OS (equivalent to reboot inside the VM).
DestroyPowers off and marks the instance for deletion. Root volume goes too. With Terraform’s expunge = true, the record is removed immediately.
View consoleOpens a VNC console via the web UI — useful when SSH is broken.

CLI:

cmk stop virtualmachine id=<vm-id>
cmk start virtualmachine id=<vm-id>
cmk reboot virtualmachine id=<vm-id>
cmk destroy virtualmachine id=<vm-id> expunge=true

Connecting

After the instance starts and you’ve forwarded a public port (see Public IPs):

ssh ubuntu@<public-ip>

Default user. Most Atlas Linux templates expose a cloud-init user that matches the OS:

TemplateUser
Ubuntuubuntu
Debiandebian
AlmaLinux / Rockyalmalinux / rocky (sometimes cloud-user)

root login is disabled by default. If SSH fails, see Can’t SSH to a VM.

Network attachment

An instance lives on one or more networks. The two shapes you’ll see:

  • Guest Network — a simple flat L2 network with NAT. Good for one-off VMs.
  • VPC tier — a subnet inside a routed VPC with its own ACL. Good for multi-tier architectures.

Inbound traffic from the public internet is controlled by:

  • Firewall rules on the Public IP (stateful) — used with Guest Networks.
  • Network ACLs on the VPC tier (stateless) — used inside VPCs.

See Public IPs and Network ACLs. Atlas does not use AWS-style Security Groups.

Advanced

  • User data — pass a cloud-init script at launch to bootstrap software unattended. See User data & cloud-init.
  • Snapshots — point-in-time copies of the root volume. See Snapshots.
  • Resize — upgrade or downgrade the Compute Offering of a running instance. Requires a stop/start. From the Console: Compute → Instances → click the VM → Service Offering → pick a new size.

Common failures

Backlinks