The result of such copy is an independent VM. The
new VM does not share any storage resources with the original.
+
+
It is possible to select a *Target Storage*, so one can use this to
migrate a VM to a totally different storage. You can also change the
disk image *Format* if the storage driver supports several formats.
+
+
NOTE: A full clone need to read and copy all VM image data. This is
usually much slower than creating a linked clone.
++
+
+Some storage types allows to copy a specific *Snapshot*, which
+defaults to the 'current' VM data. This also means that the final copy
+never includes any additional snapshots from the original VM.
+
Linked Clone::
same as the original data. Creating a linked clone is nearly
instantaneous, and initially consumes no additional space.
+
+
They are called 'linked' because the new image still refers to the
original. Unmodified data blocks are read from the original image, but
modification are written (and afterwards read) from a new
location. This technique is called 'Copy-on-write'.
+
-This implies that the original is either a read-only 'snapshot', or a
-read-only 'Template' VM. It is not possible to change the *Target
-storage* for linked clones, because this is a storage internal
-feature.
+
+This requires that the original volume is read-only. With {pve} one
+can convert any VM into a read-only <<qm_templates, Template>>). Such
+templates can later be used to create linked clones efficiently.
++
+
+NOTE: You cannot delete the original template while linked clones
+exists.
+
-NOTE: You cannot delete the original template or snapshot while
-linked clones exists.
+
+It is not possible to change the *Target storage* for linked clones,
+because this is a storage internal feature.
The *Target node* option allows you to create the new VM on a
different node. The only restriction is that the VM is on shared
storage, and that storage is also available on the target node.
-It is possible to clone a specific *Snapshot*, which defaults to the
-'current' VM data. This also means that the final copy does not
-include any additional snapshots from the original VM.
-
To avoid resource conflicts, all network interface MAC addresses gets
randomized, and we generate a new 'UUID' for the VM BIOS (smbios1)
setting.
+[[qm_templates]]
+Virtual Machine Templates
+-------------------------
+
+One can convert a VM into a Template. Such templates are read-only,
+and you can use them to create linked clones.
+
+NOTE: It is not possible to start templates, because this would modify
+the disk images. If you want to change the template, create a linked
+clone and modify that.
+
+
Managing Virtual Machines with `qm`
------------------------------------