Snapshots

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Snapshots allow you to save the state of a virtual machine for backup or templating purposes. For VMs installed from templates, live snapshots can be performed where the VM does not have to be rebooted; on operating installs from ISO, only cold snapshots are supported (snapshot after VM is turned offline).

Snapshots are billed hourly for storage space only, at $0.03 per GB per month (the first 20 GB of usage is currently free, but this is subject to change).

Creating a snapshot

Creating a snapshot in Luna Node Dynamic is easy. Simply go to the Virtual Machines sidebar entry, select your VM, and enter a snapshot label in the snapshot box. You may want to run sync before snapshotting.

If you are snapshotting a VM that was installed from an ISO image, you will need to shut down the VM before snapshotting. You will also need to have the VM adjusted so that it is set to boot to the first disk and not the CD-ROM (this is accomplished by selecting swap boot order).

Note: templates come with software called cloud-init installed that sets up SSH configuration, network interface settings, user accounts, hostname, partitions, and various other settings on the first boot. If you want a pure clone the VM, then you can remove cloud-init before taking the snapshot (apt-get/yum remove cloud-init); however, you will generally need to reconfigure the network settings on virtual machines booted from such a snapshot. See the next section for details on how to use a cloud-config startup script to change the password to something you want.

Provisioning from the snapshot

You can provision new instances from the snapshot, or re-image existing instances using the snapshot, as you would with a normal template image.

If your VM that you used for the snapshot does not have cloud-init installed, you will most likely need to reset network configuration; this can be done over VNC.

If you did remove cloud-init, the password of the default administrative user will be reset, and password authentication over SSH disabled. If you are using SSH keys, this will not be a problem -- simply select the SSH key when provisioning the new VM, and this will be forwarded to cloud-init and included in the booted VM. Otherwise, you should include a startup script to set a password and avoid disabling password authentication:

#cloud-config
password: [some password]
chpasswd: { expire: False }
ssh_pwauth: True

Replicating images between regions

Images are stored separately on each region. However, you can replicate a snapshot to another region by selecting the image from the Images sidebar tab, and then scrolling down to the image replication tool. Keep in mind that you will be billed for the storage in both regions (although you do have 20 GB free storage per region).