VMs are created by instantiating a
template, which is where you specify which
images the VM will need. Multiple VMs can share
images (regardless of any
templates that the VMs or
images may be related to) only when the
images are not persistent.
Storage for a VM is specified in terms of
disks (which are
images linked to
templates). On the Storage tab of the
template-editing screen, you can see two columns:
disks already defined on that
diskselected from the left.
You can add as many
disks as you need to a given
template, each referring to an existing
image or to a volatile
When you import an appliance from the AppMarket, that action usually downloads one
imagealong with a
template, that relates to it. You can still personalise that
templateon this Storage tab of the
When you click on a
disk of a
template (on the left column of the Storage tab), or when you click on +, you will select that
disk for editing (it will get a blue line on the left of its name and its options will show on the right column).
The options you have for a
templateyou are editing
templateyou are editing. A practical usage is to add (arbitrarily big) extra scratch space to your VM, while keeping a basic core OS image that is easy to move around in the system.
When you select Image as the storage option for a
disk in a
template, you see a table where you get to choose the
image you want from the list of your existing
images. You can sort and filter that table to help you find the
image you want to use. When you find the
image you want and you click on it, its name will appear in blue under that table.
disks are only available as long as a VM is running with them attached, and everything stored on Volatile
disks is lost once their associated VM is shut down.
disks cannot be saved-as.
Make sure you understand these facts and, therefore, place in volatile
disks only data that you are ready to loose after the VM is gone.
NOTE: By default all the projects get 10GB volatile quota. Please contact us if you need more quota than the default.
When you select Volatile Disk as the storage option for a
disk in a
template, you must specify the Size you want for the
disk. You can also specify the combination of Type and/or Format.
It does not really matter what you choose for FS and Format, because you can format your drives via the operating system tools.
Next to the name of each
disk on the list of
disks when editing a
template, you can see a black (x) button. If you click on it, the
disk will be removed from the
NOTE on Advanced options:
The Advanced options that you can see on the screen are very specific ones that we do not use every day. If you think you need to use them, we recommend you try and learn about them on the official OpenNebula documentation (for example, here). And if you find benefits in using them, please send us an e-mail to let us know: email@example.com.