Gunraid-O

I was too fixated on having everything in a single perfect pool forever. After your reply forced me to consider the idea, I realized that the storage backend would be completely invisible to users and it wouldn't matter how data is divided up. Thanks!

Hello! I have two unformatted 16 TB HDDs in a Node 804 case running Unraid version 7.2.3. I want all my storage to be in a ZFS filesystem to automatically prevent silent corruption, so it seems I won't be using the array feature. My soon-to-be-former NAS is a Synology DS923+ that contains two 16 TB HDDs and two smaller ones, with one-drive redundancy. Total data stored there is 23.1 TB. I was planning to create a ZFS pool with two single-device vdevs, transfer all the Synology data to my Unraid box, then quickly take out the old NAS's 16 TB HDDs and add them to Unraid as mirrors of the two in there. Unraid won't let me set up the pool in mirrored mode the way I want just yet; it understandably wants to pair the two HDDs. But that wouldn't leave enough room to transfer all my data. I could set it up in stripe mode so that the HDDs are left separate and provide their full storage capacity. Will I then, later, be able to change the setting to mirror and give each disk a mirror without needing, e.g., a total reformat (defeating the purpose)? Can my plan work?