I'm trying to upgrade a deployment from 8.2.2 to 8.10.2 and keep hitting the error below. The basics are pretty clear, there isn't enough disk space, but is this for just one of the nodes or the entire deployment? If its just one of the nodes I have the room to move it but I can't tell which node to move by the error details provided. This is also just an upgrade so I'm a little surprised that were hitting the issue as I would think it would be an inline upgrade with no extra disk space needed.
"details": "Current cluster data (4703203.864029884 MiB currently used) won't fit on target cluster (3932160.0 MiB available)"
Do you by any chance manually override the ram:disk ratio for deployments from time to time? I have seen that error several times in our environment (not at time of upgrade however), and then it's always related to deployments where we had done a override to the ram:disk ratio so that it temporarily can use more space than the template ratio actually provides for. If this is the case for you as well I guess it could be some action at the time of the upgrade that causes that check to be run there too.