YugabyteDB Anywhere allows you to expand a universe to add more nodes and shrink the universe to reduce the number of nodes. Typically, you do this by navigating to Universes > UniverseName > Actions > Edit Universe, as per the following illustration:
Using the Edit Universe page, you can specify the new intent for the universe. This may include a new configuration of nodes powered by a different instance type. YugabyteDB Anywhere performs these modifications through the YB-Masters powering the universe. The YB-Masters ensure that the new nodes start hosting the tablet leaders for a set of tablets in such a way that the tablet leader count remains evenly balanced across all the available nodes.
Expansion of universes created with an on-premises cloud provider and secured with third-party certificates obtained from external certification authorities follows a different workflow. For details, see Expand the universe.
For universes that use Google Cloud Provider (GCP), Amazon Web Services (AWS), or Microsoft Azure, YBA allows you to change the VM images and increase the volume size without moving the data from the old nodes to the new nodes. This is known as smart resize and is subject to the following:
For Azure universes, you can't increase the volume size for ultra SSDs.
To avoid potential data loss, you can't do a smart resize of instances with ephemeral disks. Smart resize to ephemeral disks is supported.
Smart resize cannot decrease the volume size.
You can't do a smart resize if you change any options on the Edit Universe page other than the Instance Type and the size portion of the Volume Info field.
If you change the Instance Type or both the Instance Type and the Volume Info size and then click Save, YBA gives you the option to either do a full migration of the universe and its data to new nodes, or do a smart resize, as per the following illustrations:
If you change only the Volume Info size and click Save, YBA automatically performs a smart resize.