4 drive raid 5 to larger 3 drive raid 5 possible?

[njhorn]

I currently have a maxed out 4 drive RAID 5 on a 3204t with 4TB drives, for a 12TB RAID 5... I have 3 10TB drives I want to replace with for a 20TB RAID 5, and then plan to use the empty fourth slot for an SSD cache or maybe another 10TB drive for backups in a single drive setup... Is there any easy way to go about this? I 99% sure impossible to go from a 4 drive array to a 3 drive array even with larger drives, so the only thing I can think of is to backup all data to an external 10TB drive (I have about 9.5TB of data right now), then pull all the drives and install new ones and create a new array and copy data back... But then I lose asustor settings, docker containers I have running (although I can back up the data directory and configs), etc, making it an all around pain in the ass... Any ideas?

[orion]

Your answer is correct. No way.