The datastore stores the deduplication byte-cache data.
When the Datastore is full it reaches 100% efficiency and starts managing the byte-cache in a first in first out (FIFO) queue. Hence new data replaces old data and the datastore remains at 100%.
The default allocation for the datastore partition may not be sufficient for large deployments and admins may receive an ‘insufficient disk space’ warning. In these scenarios, Admins can configure a larger datastore drive or partition. Use Solid State Drives (SSD) where possible for best performance. Refer to Changing Datastore Drives for more information.