Adding additional disks/capacity

To the best of my knowledge, what you propose to do is not possible. The only way to add capacity to a Avamar server is to add additional nodes. Which would be nodes + internal disks. The Avamar licensing itself is based on capacity and would not allow for external raid enclosures.

I agree, this should be done by adding more nodes. In test environment I could do this, but I had to break existing checkpoints and besides it is a step which is not supported. So you should add more nodes.

On the other hand, I'm not sure if adding more /data0x is supported for existing server. I guess it should be, but I never went that far in playing - avamar support might help with that.

For each node Avamar, it approved a specific hardware, including yours disks.
The cycle of routines of Avamar has to take 24 hours in Maximum.
When the discs are close to filling, the Avamar stops some fundamental tasks such as garbage collection, validation, to continue doing backups and restores.
Remember that each node is covers only the amount of processing data for which it was designed.

Maybe you can add disks to the Node Avamar, but it is not recommended, because probably the Avamar unable to process its entire task in 24 hours.
So I recommend you to add more node.
In case of the single node, you must to install a grid Avamar and transfer the data.

Best Regards.

Paulo Freitas