Templates and cloning: the difference between a linked clone and a full clone
A linked clone comes up in seconds but stays tied to the template. A full clone is independent but costs space and time. The difference surfaces the day you want to delete the template.
AtlasPVE ·
This entry answers
- proxmox create a template
- proxmox clone a vm
- linked clone vs full clone
- what is a proxmox linked clone
- what happens to clones if the template is deleted
The way to stop repeating the same installation is a template. One machine is prepared once, turned into a template, and later machines are cloned from it. Cloning then offers two roads, and the difference between them does not show on the first day.
What turning it into a template does
Once a machine becomes a template it can no longer be started, only copied. That restriction is deliberate: the template's disk has to be frozen, otherwise the machines produced from it are born different from one another. The conversion can be undone, but as a habit the template is kept apart.
The linked clone
A linked clone does not copy the template's disk, it points at it. It keeps only its own changes in its own layer. That is why it comes up in seconds and takes almost no space at first. The price is the dependency: the template cannot be deleted or moved, and the clone cannot leave the storage the template sits on.
The full clone
A full clone really copies the disk. The copying time depends on the size of the disk and the speed of the storage, and it occupies that much space from the start. In return the machine is independent: the template can be deleted, the clone can be moved to another storage, nothing is tied to anything.
Which one when
If you are producing many short lived machines, the linked clone is the right choice; test environments are the typical case. If you are building a machine that will live long, be backed up and perhaps be moved, the full clone produces fewer surprises. The deciding question is usually this: will this machine outlive the template?
Sources
Proxmox's own documentation. In English, and it has the final word on this subject.