From time to time it happens that your Vault Store partitions might get almost completely full. As we've seen Enterprise Vault has a number of protection mechanisms in place which try to prevent the situation where the partitions become 100% full. These are similar mechanisms to the 'old' Exchange reserve log files, and try to ensure that the services remain in a good state, rather than just crashing when the space is completely consumed.
But, when you're getting very close to the maximum size of your vault store partitions, what is there that you can do?
The first port of call is that you can create a new partition and close the current one. This will prevent more data being written to the current partition.
Another option would be to do the same, but, also enable and run collections on the now closed partition. But sometimes this isn't desirable...