Linked vs. Instant Clones

Clones give VMware administrators a method of making copies of virtual machines that don’t require browsing a host file system or having to track down all the configuration files to function. There are two basic types, Full and Linked.

Full clones are complete and independent copies of a virtual machine and operate separately from the original parent VM. Because they don’t share virtual disks with the original parent VM, full clones generally perform better than linked ones. However, they also take longer to create than linked clones, so there are tradeoffs.  

A linked clone is a snapshot of a virtual machine that shares virtual disks with the parent VM in an ongoing manner, which conserves disk space and allows multiple VMs to use the same software installation. Linked clones make it easier to create unique virtual machines for individual tasks. They are also easier to share amongst people who need access to the same virtual disks (like support and dev teams).

Linked Clones vs Instant Clones

Instant clones are very similar to linked clones in that they share a virtual disk of a parent VM and therefore consume less storage than a full VM. But, instant clones take it one step further by doing the same thing with memory.  Instant clones are also created off a running VM instead of a powered off one. This provides better methods of management for provisioning, updates, and memory utilization.

What Instant Clones do is give VMware administrators a way to make clones behave and function more like a container. Instant clones can be fully operational and ready to start executing quickly, where traditional clones still requires a full OS boot up that can take several minutes to deploy and configure properly.

Other benefits of Instant Clones include:

  • Significantly reduced times for a desktop to be provisioned and ready
  • Ready for users to connect to (created power on)
  • Decreased change windows
  • Storage utilization savings (instant clones don’t require databases)
  • Simplified deployment and patching for administrators
  • Lower overall solution costs
  • Reduced complexity for future upgrades

References:

Understanding Clones:

https://www.vmware.com/support/ws55/doc/ws_clone_overview.html

Instant Clones vs Linked Clones:

https://vinfrastructure.it/2017/08/instant-clones-vs-linked-clones/