Background
1. AWS volume disks can be modified once every 6 hours. Therefore, the 2nd modification request can be made after 6 hours.
2. Increasing volume size is distinct from making changes to IOPS and throughput on the backend. If you update the volume size and IOPS or throughput simultaneously, the volume size change cannot happen immediately, and the disk will not be fully ready. It has to wait 6 hours, as the volume size change request follows the IOPS or throughput change request.
If you change the instance type now, the cluster will be down because the new node cannot be provisioned from an unready Persistent Volume Claim (PVC).
Best Practices to Update Disk Volume Properties
1. Depending on your requirements, update the volume size or IOPS/throughput first, then update the other after 6 hours.
2. If you need those changes to be updated immediately, it's recommended to restore to a new cluster with the new volume settings. If the original cluster database size is large, consider enabling volume snapshot backup.