vSphere Data Protection can dynamically expand the destination backup store from 2 TB to 8 TB. Using an extended backup storage requires additional memory on the vSphere Data Protection appliance. 

VMware vSphere Data Protection Sizing Guide

Available Backup Storage Capacity

Size On Disk

Minimum Appliance Memory

0.5 TB

0.9 TB

4 GB

1 TB

1.6 TB

4 GB

2 TB

3 TB

6 GB

4 TB

6 TB

8 GB

6 TB

9 TB

10 GB

8 TB

12 TB

12 GB

VMware Backup Store Size Design Decisions

Decision ID

Design Decision

Design Justification

Design Implication

SDDC-OPS-BKP-003

Deploy the vSphere Data Protection virtual appliance initially for 4 TB of available backup storage capacity and (6 TB on-disk size. )

Handles the backup of the Management stack of a single region. The management stack currently consumes approximately 2 TB of disk space, uncompressed and without deduplication.

You must provide more NFS storage to accommodate increased disk requirements.